add custom configs to init.lua

- tab width to 4 instead of 8
- highlight extra whitespace
- trim extra whitespace on write
- removed some comments

init.lua

@@ -1,25 +1,5 @@
 --[[
 
-=====================================================================
-==================== READ THIS BEFORE CONTINUING ====================
-=====================================================================
-========                                    .-----.          ========
-========         .----------------------.   | === |          ========
-========         |.-""""""""""""""""""-.|   |-----|          ========
-========         ||                    ||   | === |          ========
-========         ||   KICKSTART.NVIM   ||   |-----|          ========
-========         ||                    ||   | === |          ========
-========         ||                    ||   |-----|          ========
-========         ||:Tutor              ||   |:::::|          ========
-========         |'-..................-'|   |____o|          ========
-========         `"")----------------(""`   ___________      ========
-========        /::::::::::|  |::::::::::\  \ no mouse \     ========
-========       /:::========|  |==hjkl==:::\  \ required \    ========
-========      '""""""""""""'  '""""""""""""'  '""""""""""'   ========
-========                                                     ========
-=====================================================================
-=====================================================================
-
 What is Kickstart?
 
   Kickstart.nvim is *not* a distribution.
@@ -28,10 +8,6 @@ What is Kickstart?
     The goal is that you can read every line of code, top-to-bottom, understand
     what your configuration is doing, and modify it to suit your needs.
 
-    Once you've done that, you can start exploring, configuring and tinkering to
-    make Neovim your own! That might mean leaving Kickstart just the way it is for a while
-    or immediately breaking it into modular pieces. It's up to you!
-
     If you don't know anything about Lua, I recommend taking some time to read through
     a guide. One possible example which will only take 10-15 minutes:
       - https://learnxinyminutes.com/docs/lua/
@@ -45,17 +21,6 @@ Kickstart Guide:
 
   TODO: The very first thing you should do is to run the command `:Tutor` in Neovim.
 
-    If you don't know what this means, type the following:
-      - <escape key>
-      - :
-      - Tutor
-      - <enter key>
-
-    (If you already know the Neovim basics, you can skip this step.)
-
-  Once you've completed that, you can continue working through **AND READING** the rest
-  of the kickstart init.lua.
-
   Next, run AND READ `:help`.
     This will open up a help window with some basic information
     about reading, navigating and searching the builtin help documentation.
@@ -70,18 +35,6 @@ Kickstart Guide:
     These are hints about where to find more information about the relevant settings,
     plugins or Neovim features used in Kickstart.
 
-   NOTE: Look for lines like this
-
-    Throughout the file. These are for you, the reader, to help you understand what is happening.
-    Feel free to delete them once you know what you're doing, but they should serve as a guide
-    for when you are first encountering a few different constructs in your Neovim config.
-
-If you experience any errors while trying to install kickstart, run `:checkhealth` for more info.
-
-I hope you enjoy your Neovim journey,
-- TJ
-
-P.S. You can delete this when you're done too. It's your config now! :)
 --]]
 
 -- Set <space> as the leader key
@@ -161,6 +114,19 @@ vim.opt.scrolloff = 10
 -- See `:help 'confirm'`
 vim.opt.confirm = true
 
+-- set tabs to 4 spaces (default is 8)
+vim.bo.tabstop = 4
+vim.bo.shiftwidth = 4
+vim.bo.softtabstop = 4
+
+-- highlight ExtraWhitespace
+-- TODO: does not seem to clear all whitespace (-> did not work for yaml file)
+vim.api.nvim_set_hl(0, 'ExtraWhitespace', {
+  fg = nil,
+  bg = '#ff80ff', -- Hex color
+})
+vim.cmd [[match ExtraWhitespace /\s\+$/]]
+
 -- [[ Basic Keymaps ]]
 --  See `:help vim.keymap.set()`
 
@@ -670,7 +636,7 @@ require('lazy').setup({
       --        For example, to see the options for `lua_ls`, you could go to: https://luals.github.io/wiki/settings/
       local servers = {
         -- clangd = {},
-        -- gopls = {},
+        gopls = {},
         -- pyright = {},
         -- rust_analyzer = {},
         -- ... etc. See `:help lspconfig-all` for a list of all the pre-configured LSPs