Add a cargo rule

README.md

@@ -146,6 +146,7 @@ sudo pip install thefuck --upgrade
 The Fuck tries to match a rule for the previous command, creates a new command
 using the matched rule and runs it. Rules enabled by default are as follows:
 
+* `cargo` – run `cargo build` instead of `cargo`;
 * `cd_correction` – spellchecks and correct failed cd commands;
 * `cd_mkdir` – creates directories before cd'ing into them;
 * `cd_parent` – changes `cd..` to `cd ..`;