Fix typos with codespell

Using codespell 1.14.0.

Method:
```
$ cat > ../godot-word-whitelist.txt << EOF
ang
doubleclick
lod
nd
numer
que
te
unselect
EOF
$ codespell -w -q 3 -I ../godot-word-whitelist.txt --skip="./thirdparty,*.po"
$ git diff // undo unwanted changes
```

editor/find_in_files.cpp

@@ -321,7 +321,7 @@ FindInFilesDialog::FindInFilesDialog() {
 	_search_text_line_edit->connect("text_entered", this, "_on_search_text_entered");
 	gc->add_child(_search_text_line_edit);
 
-	gc->add_child(memnew(Control)); // Space to mantain the grid aligned.
+	gc->add_child(memnew(Control)); // Space to maintain the grid aligned.
 
 	{
 		HBoxContainer *hbc = memnew(HBoxContainer);