feat: add mermaid language configuration

[CatBraaain]

Add language configuration and support features bellow

• Comment toggling
• Brackets definition
• Autoclosing
• Autosurrounding
• Folding
• Indentation Rules

Code snippets https://code.visualstudio.com/api/language-extensions/language-configuration-guide

Test

I'm very new to pull request, I welcome any feedback.

[CatBraaain]

and support embed mermaid in markdown

[bpruitt-goddard]

I like the comment toggling and the embedded mermaid in markdown support, but I worry that the bracket matching/autoclosing will give issues. Consider the relationship syntax in ER diagrams. This change will make it less clear that they are valid. For example I'm seeing these brace closing errors in the ER test file:

A similar problem happens when trying to create new relationships - the bracket is attempted to autoclose ,which is not relevant for the relationship. Could we remove the brace functionality from here?

[CatBraaain]

Thanks for reviewing. After receiving your feedback, I found some similar problems in curl bracket and square bracket.

I removed some features what I'm not sure it affects any problems.

Current feature

• Comment toggling
  • in mermaid language
  • in embedded mermaid block in markdown language

[bpruitt-goddard]

The PR looks good, there are just some prettier issues in a file. Can you fix these before merge?

Checking formatting... [warn] syntaxes/mermaid.tmLanguage-markdown.yaml [warn] Code style issues found in the above file. Run Prettier to fix. Problem running prettier with --check */.{js,yaml,md}

[CatBraaain]

Thanks for reviewing. I ran npx prettier --write syntaxes/mermaid.tmLanguage-markdown.yaml and commit it again.

[CatBraaain]

Thanks to you, I'm glad I succeeded my first pull request.

[bpruitt-goddard]

Awesome job on your first PR! Thanks for picking this project to contribute to!