Keep certain files from displaying in diffs

Use the linguist-generated attribute to mark or unmark paths that you would like to be collapsed by default in diffs.

For example, to mark search/index.json as a generated file, add this line to .gitattributes:

search/index.json linguist-generated=true

Closes: #4832 (closed) gitlab#17647 (closed)

Signed-off-by: Maksim Paskal paskal.maksim@gmail.com