Add editorconfig to fix tab width on github

Signed-off-by: Mahyar Koshkouei <deltabeard@users.noreply.github.com>

.editorconfig

@@ -0,0 +1,15 @@
+# EditorConfig is awesome: http://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+# Set tab indentation
+[*.{c,h}]
+indent_style = tab
+indent_size = 4
+max_line_length = 80