docs: update FAQ

doc/faq/README.md

@@ -1,3 +1,22 @@
 # FAQ
 
 - [Installation Failures](./install-failed.md)
+
+Always run `:checkhealth` to check problems.
+
+## Syntax parsed errors, highlights errors, indent errors
+
+These features are based on treesitter.
+
+When you first install, check treesitter parsers installed via `:TSIntall`.
+
+When you updated neovim or treesitter, run `:TSUpdate` to update all installed treesitter parsers to latest.
+
+See [doc/treesitter.md](../treesitter.md) for details.
+
+## Client quit with exit code and signal
+
+If you see the notify message `Client <number> quit with exit code <number> and signal <number>`.
+
+Open `:LspInfo` window to check the LSP clients. There may be some clients which no buffer attached.
+Open `:Mason` window to reinstall or update the LSP client.

doc/faq/install-failed.md

@@ -2,6 +2,8 @@
 
 [English](./install-failed.md) | [中文](./install-failed.zh.md)
 
+Always run `:checkhealth` to check problems.
+
 ## ERROR [mason-tool-installer] luaformatter: failed to install
 
 If you are using MacOS, try to install luarocks by `brew install luarocks`, or upgrade it.

doc/faq/install-failed.zh.md

@@ -2,6 +2,8 @@
 
 [English](./install-failed.md) | [中文](./install-failed.zh.md)
 
+总是运行 `:checkhealth` 来检查问题。
+
 ## ERROR [mason-tool-installer] luaformatter: failed to install
 
 如果你使用 MacOS，用 `brew install luarocks` 来安装 luarocks，或者把它升级到最新版本。