Add EditorConfig

.editorconfig

@@ -0,0 +1,15 @@
+root = true
+
+[*]
+charset = utf8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.agc]
+indent_style = tab
+tab_width = 8
+
+[*.md]
+indent_style = space
+indent_size = 2

CONTRIBUTING.md

@@ -19,7 +19,7 @@ to 2 blank lines in a row.
   defined but never used. Read more about it in chrislgarry/Apollo-11/#159
 
 ## Formatting
-[AGC Assembly][4] for Sublime Text 3 and [Language AGC][5] for Atom
+GitHub, [AGC Assembly][4] for Sublime Text 3 and [Language AGC][5] for Atom
  will ensure you're using the correct formatting automatically.
 
 [AGC Assembly][3] for Visual Studio Code provides language-specific