Release 13.24.1

See merge request gitlab-org/gitlab-shell!580

Reuse Gitaly connections and sidechannel

See merge request gitlab-org/gitlab-shell!575

Default to info level for an empty log-level

Closes #550

See merge request gitlab-org/gitlab-shell!579

I'd assumed that the `omitempty` directive for LogLevel in
internal/config/config.go would get us this behaviour. If it did, we
wouldn't have had to specify the default twice. Unfortunately, it
doesn't, which is to say that given a config file like:

```
log_level:
```

The default *is* overridden by the empty string.

It's an easy enough fix.

Changelog: fixed

When gitlab-sshd has been introduced we've started running our
own SSH server. In this case we're able to cache and reuse
Gitaly connections and Registry.

It helps to reduce memory usage.

Update Gitaly dependency to v14.9.0-rc1

See merge request gitlab-org/gitlab-shell!578

Release 13.24.0

See merge request gitlab-org/gitlab-shell!577

Upgrade golang to 1.17.7

See merge request gitlab-org/gitlab-shell!576

Add more metrics for gitlab-sshd

See merge request gitlab-org/gitlab-shell!574

- Counter of HTTP merge requests
- Gauge of HTTP requests currently being performed
- Gauge of connections currently handled by gitlab sshd

Move code guidelines to doc/beginners_guide.md

See merge request gitlab-org/gitlab-shell!572

Bring the page a lot closer to GitLab tone and style. Not perfect,
but we've gotta start somewhere.

It helps to have less verbose README.md

Add docs for full feature list

See merge request gitlab-org/gitlab-shell!571

Add aqualls as codeowner for docs files

See merge request gitlab-org/gitlab-shell!573

These pages should get credited to Source Code. (I should also
check about CODEOWNERS entries too.)

Do an initial cleanup pass:

- Line wraps
- Change 'allows' to 'enables'
- Clean up syntax highlighting
- Fix spelling and capitalization
- Standardize on colons at the end of the introductory sentences

Shouldn't start with a leading slash.

Describe what Gitlab Shell is capable of

Release 13.23.2

See merge request gitlab-org/gitlab-shell!570

Bump labkit version to 1.12.0

See merge request gitlab-org/gitlab-shell!569

It also bumps minor versions of its dependencies

Add title and correct copyright notice to license

See merge request gitlab-org/gitlab-shell!568

Update LICENSE to 2022

See merge request gitlab-org/gitlab-shell!566

Handle and log unhandled errors

See merge request gitlab-org/gitlab-shell!564

Currently, we don't process the results of this execution,
because it's not really imprortant

Let's at least log the err if the execution went wrong

That will also make Vulnerability report happy

Bump go-proxyproto package

See merge request gitlab-org/gitlab-shell!563

When building, ignore the vendor/ directory if present

Closes #539

See merge request gitlab-org/gitlab-shell!565