chore: backport retro compatible commits for the Docusaurus v2.2 release (#8264)

Co-authored-by: Jan Peer Stoecklmair <jan.peer.stoecklmair@dynatrace.com>
Co-authored-by: Joshua Chen <sidachen2003@gmail.com>
Co-authored-by: sebastienlorber <lorber.sebastien@gmail.com>
Co-authored-by: Sébastien Lorber <slorber@users.noreply.github.com>
Co-authored-by: LittleboyHarry <littleboyharry@qq.com>
Co-authored-by: Mikey O'Toole <mikey@homotechsual.dev>
Co-authored-by: Jan Peer Stöcklmair <jan.oster94@gmail.com>
Co-authored-by: Nguyễn Thành Nam <namnguyenthanh.work@gmail.com>
Co-authored-by: Sanjaiyan Parthipan <parthipankalayini@gmail.com>
Co-authored-by: Ramazan SANCAR <ramazansancar4545@gmail.com>
Co-authored-by: mturoci <64769322+mturoci@users.noreply.github.com>
Co-authored-by: Adnan Hashmi <56730784+adnanhashmi09@users.noreply.github.com>
Co-authored-by: Pranav Joglekar <pranav2000joglekar@gmail.com>
Co-authored-by: forgeRW <20483211+forgeRW@users.noreply.github.com>
Co-authored-by: Masahiko Hara <pasora@sfc.wide.ad.jp>
Co-authored-by: Johan Fagerberg <johanringmann@gmail.com>
Co-authored-by: John Reilly <johnny_reilly@hotmail.com>
Co-authored-by: Sam Wall <oss@samuelwall.co.uk>
Co-authored-by: Jeferson S. Brito <30840709+jeferson-sb@users.noreply.github.com>
Co-authored-by: evan <evanmccarthy@outlook.com>
Co-authored-by: Xabier Lahuerta Vazquez <xlahuerta@protonmail.com>
Co-authored-by: Forresst <forresst17@gmail.com>
Co-authored-by: Shanmughapriyan S <priyanshan03@gmail.com>
Co-authored-by: Alexey Pyltsyn <lex61rus@gmail.com>

website/sidebars.js

@@ -82,6 +82,7 @@ const sidebars = {
             'guides/markdown-features/links',
             'guides/markdown-features/plugins',
             'guides/markdown-features/math-equations',
+            'guides/markdown-features/diagrams',
             'guides/markdown-features/head-metadata',
           ],
         },