feat(documentation): add installation instructions for Vim 8+ (#231)

Closes #207

Author: novusnota

CHANGELOG.md

@@ -7,6 +7,7 @@ All notable changes to this project will be documented in this file.
 ### Improvements
 
 - feat(documentation): add missing functions to `stubs/` and adjust the format to match the rest of other stdlib doc `///` comments in https://github.com/tact-lang/tact-language-server/pull/189
+- feat(documentation): add installation instructions for Vim 8+ in https://github.com/tact-lang/tact-language-server/pull/231
 
 ### Fixed
 

README.md

@@ -119,6 +119,69 @@ Setup steps:
     require'lspconfig'.tact.setup {}
     ```
 
+### Vim
+
+Prerequisites:
+
+- Vim 8 or newer
+- Async LSP Client for Vim: [vim-lsp](https://github.com/prabirshrestha/vim-lsp)
+- Plugin for Tact: [tact.vim](https://github.com/tact-lang/tact.vim)
+
+Recommended, but not required:
+
+- Auto-configurations for many language servers: [vim-lsp-settings](https://github.com/mattn/vim-lsp-settings)
+
+Setup steps:
+
+1. Install the [tact.vim](https://github.com/tact-lang/tact.vim) if it isn't already installed. Prefer using a non-builtin plugin manager to easily get new updates.
+
+2. Install the [vim-lsp](https://github.com/prabirshrestha/vim-lsp) plugin if it isn't already installed. For that, use [vim-plug](https://github.com/junegunn/vim-plug) or the built-in package manager of Vim 8+, see [`:help packages`](https://vimhelp.org/repeat.txt.html#packages).
+
+- If it wasn't installed before, you'll need to setup basic keybindings with the language client. Add the following to your `~/.vimrc` (or `~/_vimrc` if you're on Windows), or modify to your preferences:
+
+    ```vim
+    function! s:on_lsp_buffer_enabled() abort
+        setlocal omnifunc=lsp#complete
+        setlocal signcolumn=yes
+        if exists('+tagfunc') | setlocal tagfunc=lsp#tagfunc | endif
+        nmap <buffer> gd <plug>(lsp-definition)
+        nmap <buffer> gs <plug>(lsp-document-symbol-search)
+        nmap <buffer> gS <plug>(lsp-workspace-symbol-search)
+        nmap <buffer> gr <plug>(lsp-references)
+        nmap <buffer> gi <plug>(lsp-implementation)
+        nmap <buffer> gt <plug>(lsp-type-definition)
+        nmap <buffer> <leader>rn <plug>(lsp-rename)
+        nmap <buffer> [g <plug>(lsp-previous-diagnostic)
+        nmap <buffer> ]g <plug>(lsp-next-diagnostic)
+        nmap <buffer> K <plug>(lsp-hover)
+        nnoremap <buffer> <expr><c-f> lsp#scroll(+4)
+        nnoremap <buffer> <expr><c-d> lsp#scroll(-4)
+
+        let g:lsp_format_sync_timeout = 1000
+        autocmd! BufWritePre *.rs,*.go call execute('LspDocumentFormatSync')
+
+        " refer to doc to add more commands
+    endfunction
+
+    augroup lsp_install
+        au!
+        " call s:on_lsp_buffer_enabled only for languages that has the server registered.
+        autocmd User lsp_buffer_enabled call s:on_lsp_buffer_enabled()
+    augroup END
+    ```
+
+3. Add the following to your `~/.vimrc` (or `~/_vimrc` if you're on Windows):
+
+    ```vim
+    if executable('node')
+      au User lsp_setup call lsp#register_server({
+            \ 'name': 'tact',
+            \ 'cmd': {server_info->['node', '/absolute/path/to/language-server/dist/server.js', '--stdio']},
+            \ 'allowlist': ['tact'],
+            \ })
+    endif
+    ```
+
 ### Sublime Text
 
 1. Install [LSP](https://packagecontrol.io/packages/LSP) package: