feat: add treesitter highlighting for gotmpl

Add detection, treesitter highlighting, and tab spacing settings for
gotmpl files.

nvim/after/ftplugin/gotmpl.lua

@@ -0,0 +1,7 @@
+local setlocal = vim.opt_local
+
+-- Tabs and spaces
+setlocal.expandtab = false
+setlocal.tabstop = 8
+setlocal.shiftwidth = 8
+setlocal.softtabstop = 8

nvim/lua/ftdetect/gotmpl.lua

@@ -0,0 +1,4 @@
+vim.api.nvim_create_autocmd(
+  { "BufNewFile", "BufRead"},
+  { pattern = {"*.gotmpl"}, command = "set ft=gotmpl" }
+)

nvim/lua/ftdetect/init.lua

@@ -1 +1,2 @@
 require("ftdetect.jsonnet")
+require("ftdetect.gotmpl")

nvim/lua/plugins/config/treesitter.lua

@@ -9,6 +9,8 @@ treesitter.setup {
     "bash",
     "go",
     "gomod",
+    "gosum",
+    "gotmpl",
     "hcl",
     "json",
     "lua",