[kanvas-site] Add custom 404 page#170

Oluwatunmise-olat wants to merge 3 commits intomeshery-extensions:mastermeshery-extensions/kanvas-site:masterfrom

Oluwatunmise-olat:feat/add-404-pageOluwatunmise-olat/kanvas-site:feat/add-404-pageCopy head branch name to clipboard