Fix spelling mistake (#30)

Author: Rspoon3

CONTRIBUTING.md

@@ -79,7 +79,7 @@ contributors.
    ❌ Refactor networking layer.
    ```
 1. The subject is ideally 50 characters or less (otherwise, 72 characters or less).
-1. The subject is separated from the body with a blank line (critical unless the body is ommitted entirely).
+1. The subject is separated from the body with a blank line (critical unless the body is omitted entirely).
 1. The subject and body are free of whitespace errors and typos.
 1. The body uses proper punctuation and capitalization.
 1. The body has a line length of 72 characters or less.