feat(nvim): add gitsigns to null-ls code actions

lua/opdavies/lsp/null-ls.lua

@@ -14,13 +14,15 @@ end
 
 local augroup = vim.api.nvim_create_augroup("LspFormatting", {})
 
-local completion = null_ls.builtins.completion
+local code_actions = null_ls.builtins.code_actions
 local diagnostics = null_ls.builtins.diagnostics
 local formatting = null_ls.builtins.formatting
 
 null_ls.setup {
   sources = {
     formatting.phpcbf,
+    code_actions.gitsigns,
+
     formatting.markdownlint,
     formatting.prettier,
     formatting.rustywind,