* Translate challenge subtitles and example challenge text to Spanish
* Corrected errors in syntax and punctuation
* Multiple corrections of it/s to its plus other grammar corrections
* Correction and added paragraph to CSS Flex article
* Corrected my own typo
* Corrected capitalization, American spellings and typos
* Fixing typo: Implement the Serialization of a Passport User
Fixing typo in "Implement the Serialization of a Passport User" curriculum page under "Advanced Node and Express" topic
* Fix typo in 'logging a user out' page
Fixing typo in 'logging a user out' page