Expand the .editorconfig file

Even though these are not relevant to this specific repository, the file is intended for use unmodified in all Arduino
tooling projects and so it's easiest to define the standard formatting styles of all file types.

Author: per1234

.editorconfig

@@ -24,7 +24,7 @@ indent_style = space
 indent_size = 2
 indent_style = space
 
-[*.go]
+[*.{go,mod}]
 indent_style = tab
 
 [*.java]
@@ -39,6 +39,10 @@ indent_style = space
 indent_size = unset
 indent_style = space
 
+[*.proto]
+indent_size = 2
+indent_style = space
+
 [*.py]
 indent_size = 4
 indent_style = space
@@ -50,3 +54,6 @@ indent_style = space
 [*.{yaml,yml}]
 indent_size = 2
 indent_style = space
+
+[{.gitconfig,.gitmodules}]
+indent_style = tab