feat: Add support for ripgrep in "find_files" builtin (#70)

* feat: Add support for ripgrep in "find_files" builtin

* docs: Add mention about "ripgrep" for find_files builtin

lua/telescope/builtin.lua

@@ -366,15 +366,17 @@ end
 builtin.find_files = function(opts)
   opts = opts or {}
 
-  local fd_string = nil
+  local find_command = nil
   if 1 == vim.fn.executable("fd") then
-    fd_string = "fd"
+    find_command = { 'fd', '--type', 'f' }
   elseif 1 == vim.fn.executable("fdfind") then
-    fd_string = "fdfind"
+    find_command = { 'fdfind', '--type', 'f' }
+  elseif 1 == vim.fn.executable("rg") then
+    find_command = { 'rg', '--files' }
   end
 
-  if not fd_string then
-    print("You need to install fd or submit PR for different default file finder :)")
+  if not find_command then
+    print("You need to install either fd or rg. You can also submit a PR to add support for another file finder :)")
     return
   end
 
@@ -387,7 +389,7 @@ builtin.find_files = function(opts)
   pickers.new(opts, {
     prompt = 'Find Files',
     finder = finders.new_oneshot_job(
-      {fd_string, '--type', 'f'},
+      find_command,
       opts
     ),
     previewer = previewers.cat.new(opts),