add ssh config language

[atakanyenel]

This PR adds the new language SSHCONFIG for ssh configuration files and it's respective syntax highlighting

Description

This PR is about issue #3450 . The sample code is also taken from a reply to this issue.

Checklist:

• I am associating a language with a new file extension.

  • The new extension is used in hundreds of repositories on GitHub.com
    • Search results for each extension:
      • https://github.com/search?utf8=%E2%9C%93&type=Code&ref=searchresults&q=extension%3AFOOBAR+KEYWORDS+NOT+nothack
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • [URL to each sample source, if applicable]
    • Sample license(s):
  • I have included a change to the heuristics to distinguish my language from others using the same extension.

• I am adding a new language.

  • The extension of the new language is used in hundreds of repositories on GitHub.com.
    • Search results for each extension:
      • https://github.com/search?q=extension%3Asshconfig+NOT+nothack&type=Code
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • Language ssh-config #3450 (comment)
    • Sample license(s):
  • I have included a syntax highlighting grammar: https://github-lightshow.herokuapp.com/?utf8=%E2%9C%93&scope=from-url&grammar_format=cson&grammar_url=https%3A%2F%2Fraw.githubusercontent.com%2FAlhadis%2Flanguage-etc%2Fmaster%2Fgrammars%2Fssh-config.cson%3Fa%3D1&grammar_text=&code_source=from-url&code_url=https%3A%2F%2Fpastebin.com%2Fraw%2FUWWuQR0K&code=
  • I have updated the heuristics to distinguish my language from others using the same extension.

• I am fixing a misclassified language

  • I have included a new sample for the misclassified language:
    • Sample source(s):
      • [URL to each sample source, if applicable]
    • Sample license(s):
  • I have included a change to the heuristics to distinguish my language from others using the same extension.

• I am changing the source of a syntax highlighting grammar

  • Old: https://github-lightshow.herokuapp.com/
  • New: https://github-lightshow.herokuapp.com/

• I am updating a grammar submodule

I'm updating vendor/grammars/language-etc as sshconfig grammar file is committed to this repo by @Alhadis

• I am adding new or changing current functionality
  • I have added or updated the tests for the new or changed functionality.

[Alhadis]

Looks good, @atakanyenel! 👍 I've pointed out some things that need fixing.

Additionally, it looks like CI is failing because of an outdated license cache. You may need to run script/licensed locally, commit the updated licenses, and update your branch.

[Alhadis]

LGTM. 👍 @pchaigno, any input?

[atakanyenel]

Can A rework be done to catch the licence error on the local dev stage ?

[Alhadis]

Running brake exec rake tests should have picked up on the stale license cache... 🤔

[Alhadis]

Looks great, thanks for your patience!

[atakanyenel]

Thanks for the sshconfig grammar & support 👍 great community !

[pchaigno]

I left a couple of comments below.

Overall the filenames look ok. There might even be a couple more to add.
The file extensions, however, all have low usage.

[pchaigno]

Looks like something went wrong when merging/rebasing...

[pchaigno]

Looks like you committed changes to this file by mistake.

[atakanyenel]

Sorry for the force-push, I turned the PR into a mess at one point. I respected the comments and made the push accordingly.

[Alhadis]

Nudging @pchaigno for a follow-up on their change-request review. 😉

I could dismiss your review for you, but that would be rude...

[pchaigno]

Looks good to me! Sorry for the delay and thanks for your patience @atakanyenel!