fix: prevent mason setup from being run twice (#1298)

* fix: prevent mason setup from being run twice

Addresses nvim-lua/kickstart.nvim#1297

Currently, we're calling `require('mason').setup(...)` twice:
* once when setting it as a dependency of `nvim-lspconfig` (since we set
        `config = true`)
* once in the `config` function we define for `nvim-lspconfig`

Calling setup twice can cause issues with, e.g., setting the `PATH`
option: you might append Mason's bin dir in one setup call and prepend
it in the other.

We've kept the setup of `mason` in the `nvim-lspconfig` dependencies
table since leaving it to the `config` function caused some
plugin-loading-order related issues in the past. See:
* nvim-lua/kickstart.nvim#210
* nvim-lua/kickstart.nvim#554
* nvim-lua/kickstart.nvim#555
* nvim-lua/kickstart.nvim#865

* docs: tweak comments per review feedback

README.md

@@ -158,3 +158,14 @@ git clone https://github.com/ppizarro/my.vim ~/.config/nvim
 `gc` - Toggles the region using linewise comment
 `gb` - Toggles the region using blockwise comment
 ```
+
+# Update
+
+To check the current status of installed tools and/or manually install
+other tools, you can run
+   :Mason
+
+You can press `g?` for help in this menu.
+
+`mason` had to be setup earlier: to configure its options see the
+`dependencies` table for `nvim-lspconfig` above.

lua/pp/plugins/lsp/init.lua

@@ -25,7 +25,9 @@ return {
     "neovim/nvim-lspconfig",
     dependencies = {
       -- Automatically install LSPs and related tools to stdpath for Neovim
-      { "williamboman/mason.nvim", config = true }, -- NOTE: Must be loaded before dependants
+      -- Mason must be loaded before its dependents so we need to set it up here.
+      -- NOTE: `opts = {}` is the same as calling `require('mason').setup({})`
+      { "williamboman/mason.nvim", opts = {} },
       { "williamboman/mason-lspconfig.nvim" },
       { "WhoIsSethDaniel/mason-tool-installer.nvim" },