Added pull request tutorial

Added how to create remote upstream

Small formatting corrections

Finished instructions on syncing forked repository

Formatting changes

Added instructions on how to issue pull request

Updated formatting

Updated wording

Added merge commits section

Fixed some formatting

Fixed formatting with code example

Added git reset section

Fixed some formatting

Removed number list

Clarified editor

Fixed grammar error

Added link for git reset

Fixed grammar error

Cleaned up wor