Fix whitespace and typos (#1481)

* Remove EOL whitespace in files other than docs

* Break paragraphs into lines

See http://rhodesmill.org/brandon/2012/one-sentence-per-line/ for the rationale

* Fix various typos

* Remove EOL whitespace in docs/commands/*.md

crates/nu-cli/src/env/environment_syncer.rs

@@ -208,7 +208,7 @@ mod tests {
                 assert_eq!(actual, expected);
             });
 
-            // Now confirm in-memory environment variables synced appropiately
+            // Now confirm in-memory environment variables synced appropriately
             // including the newer one accounted for.
             let environment = actual.env.lock();