website/integrations: add The Lounge (#11971)

* Add The Lounge Integration guide

Signed-off-by: Michael Brünen <34708235+OddMagnet@users.noreply.github.com>

* Add The Lounge to sidebar, fix Note section formatting

* Fix folder name (1/2)

* Fix folder name (2/2)

* Update website/integrations/services/thelounge/index.md

Co-authored-by: Tana M Berry <tanamarieberry@yahoo.com>
Signed-off-by: Michael Brünen <34708235+OddMagnet@users.noreply.github.com>

* Update website/integrations/services/thelounge/index.md

Co-authored-by: Tana M Berry <tanamarieberry@yahoo.com>
Signed-off-by: Michael Brünen <34708235+OddMagnet@users.noreply.github.com>

* Fix cutoff sentence

Signed-off-by: Michael Brünen <34708235+OddMagnet@users.noreply.github.com>

* Linter fixes

---------

Signed-off-by: Michael Brünen <34708235+OddMagnet@users.noreply.github.com>
Co-authored-by: Tana M Berry <tanamarieberry@yahoo.com>

website/sidebarsIntegrations.js

@@ -33,6 +33,7 @@ module.exports = {
                         "services/roundcube/index",
                         "services/sharepoint-se/index",
                         "services/slack/index",
+                        "services/thelounge/index",
                         "services/vikunja/index",
                         "services/wekan/index",
                         "services/wiki-js/index",