Create CI jobs to only build windows helper images when on branches that
are not master or branches related to docs for both Windows server 1809
and 1803

Create CI job to publish windows helper images when on master branch for
both Windows server 1809 and 1803.

Use same the environment variable `IS_LATEST` that is used for the bash
script to check when to create and push the latest tag.

The decision for using PowerShell for windows is because we cannot
build/save/export windows containers to a non-Windows image so we to use
a scripting language native to windows. Bash can be used but it would be
in a subsystem which is not ideal. This script will be used inside of
GitLab CI in a future MR when the infrastructure has set up
https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/5952.

This PowerShell script is doing a few things different than
`release_docker_images` for the helper images. In the bash script we
expect the helper images are already built and exported using `docker
export` but for windows containers when you run the command you get `the
daemon on this operating system does not support exporting Windows
containers`. This script will build the docker container and then push
it to the docker registry hub.

Add the initial Dockerfiles for windows server, using servercore as the
bilder image, which gives us access to powershell, and nanoserver as the
final image to keep the image as small as possible.

These Dockerfiles expect to have
`./binaries/gitlab-runner-helper.win_amd64.exe` built already, it will
NOT build the binary itself to stay consistent with the Linux
Dockerfiles and reduce duplication.

We need to add a Dockerfile for each windows server version that we want
to support, because when you run windows containers the host machine and
the container version has to match. For example of your machine that
has docker installed in running `ltsc2019` the containers it can run are
only of the version `ltsc2019`

Start compiling and storing  the windows helper binary.

GitLab Runner helper is built using `make docker` which builds the
binary, creates a Docker container and extract the files system of that
container for publishing at a later stage.

Because of  https://gitlab.com/gitlab-org/gitlab-runner/issues/3755 we
have to split this command up so we generate the binaries and the docker
archive separately since Windows containers cannot be built on Linux systems
or vice versa.

We are keeping the binary generation in one command to have both Windows
and Linux binaries consistent, and built them on a Linux platform where
`make` is installed. The make command already sets up the $GOPATH,
dependencies and environment for building the binaries so there is no
point of duplicating that. Then diverge when building the docker
containers, since they have to be done on different platforms.  Windows
does have GNUMake http://gnuwin32.sourceforge.net/packages/make.htm but
it's fairly outdated and doesn't seem to work when installing it on
Windows server 2019.

Drop support for `USE_PRECOMPILED_IMAGES` since it's just extra
complexity that is not needed, and it doesn't seem to be used anywhere.
If the user runs `make helper-docker` and the binaries are already
present they are not rebuild.

Add `build_simple' to `help' make target

See merge request gitlab-org/gitlab-runner!1212

When I needed to fix a bug and quickly build and test it I was
confounded by the build apparently detecting my supported qemu targets
and launching docker containers to build for all archs, but failing,
thus leaving me stuck and unable to test my fix.  If build_simple were
documented in `make help' I would have found my answer much sooner.

Fix anchors in Runner documentation

See merge request gitlab-org/gitlab-runner!1216

Document OS deprecations for 12.0

See merge request gitlab-org/gitlab-runner!1210

Merge branch '3755-helper-image-for-windows-container-execution-bash-gitalb-runner-cache' into 'master'

Migrate cache bash script to Go for helper image

See merge request gitlab-org/gitlab-runner!1201

`gitlab-runner-cache` is being used to change the permissions, port
this script to Go so that it is cross-platform.

The bash script loops through the paths but separating them with
spaces, which will not work for Windows since it is a lot more common to
have a directory with spaces. Looking at the usage of the script we
always send 1 path so the loop was a bit redundant.

For now do not use the Go command since changing it will result into a
breaking change. This will be done behind a feature flag which will done
in a feature MR.

https://gitlab.com/gitlab-org/gitlab-runner/issues/3755

Add test for runner build limit

See merge request gitlab-org/gitlab-runner!1186

In 12.0 we get the chance to do breaking changes. Mark as deprecated any
OS that will reach end of life before the 12.0 milestone.

Follow style convention for documentation

See merge request gitlab-org/gitlab-runner!1213

An admin can set the max build a specific executor can run, create a test case
scenario to check if we return the correct errors.

Increase test timeout for shell executor

See merge request gitlab-org/gitlab-runner!1214

Most of the tests for the shell executor are downloading git
repositories over the network. This can sometimes take longer than
expected for multiple networking reasons. 10 seconds is a bit too
aggressive, which resulted in developers just retrying the test. Bump it
up to 20 seconds to give it a bit more time before we fail the test.

Update the TIP to follow style guide provided in https://docs.gitlab.com/ee/development/documentation/styleguide.html#tip

Resolve "Docs feedback: Run runner on kubernetes"

Closes #3973

See merge request gitlab-org/gitlab-runner!1185

* 11-8-stable:
  Update CHANGELOG for v11.8.0

Migrate service wait script to Go

See merge request gitlab-org/gitlab-runner!1195

Fix spelling and other minor improvements

See merge request gitlab-org/gitlab-runner!1207

Incorporate feedback from MR with topic overview, individual sections for each activity and general rewording and restructuring for clarity and readability.

Correct spelling of timed out in literals

See merge request gitlab-org/gitlab-runner!1121

Document creation of Docker volumes passed with docker exec --docker-volumes

See merge request gitlab-org/gitlab-runner!1120