Extend cargo-spellcheck to cover entire repository including .github directory

.cargo/config.toml

@@ -10,7 +10,7 @@ incremental = true
 # TODO(aatifsyed): remove - this can be pushed out to readme
 # In all cases, pass --cfg=tokio_unstable for tokio console integration
 # See (https://github.com/ChainSafe/forest/pull/2245)
-# Note that this may be overriden by user configuration at ~/.cargo/config.toml
+# Note that this may be overridden by user configuration at ~/.cargo/config.toml
 rustflags = ["--cfg=tokio_unstable"]
 
 [net]