Twig mods not working right and reverting doesn't work properly, only delete revision entirely: solved

I was trying to move the category navbar up on top of the store name and logo. When I did, the category appeared as a long expanded list of categories and subcategories in a vertical line. When I hit revert the navbar was at the position it was before but was no longer a bar, it was that ugly vertical list. I finally did a diff comparing the original pristine header.twig with the changed one and the one I got after revert. What I discovered is that in the two new versions both changed and reverted the header link to one of the stylesheets used by the navbar had disappeared in both my changed version and in the reverted version. I manually added the link back to the twig file and my navbar was a navbar and reverted it puta navbar in the old place with no toubles.

See this FAQ when modifying TWIG files: viewtopic.php?f=134&t=215776#p718325