Add syntax highlighting and language server.

[xxmao123]

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• N
• Y

fix #1

2. What is the scope of this PR (e.g. component or file name):

init.lua
lua/lsp/init.lua
lua/lsp/handlers.lua
syntax/kcl.vim
ftplugin/kcl.lua

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

Add some basic functions and language server.

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

[He1pa]

Is this support for vim or neovim？

[xxmao123]

Is this support for vim or neovim？

Yes, it supports for neovim.

[Peefy]

LGTM