[wiki migration] Remaining pages under docs/about/ (#148782)

This moves the wiki pages that have a final destination under docs/about/ as planned in [flutter.dev/go/migrate-flutter-wiki-spreadsheet](https://docs.google.com/spreadsheets/d/1x65189ZBdNiLRygpUYoU08pwvXD4M-Z157c6pm8deGI/edit?usp=sharing)

It also adds the team labels to the label bot for future PRs.

Changes to the content were only updating cross links, or links to refer to the main branch rather than master.
Remaining links to the wiki will be updated once all other pages have finished moving, they still work in the meantime.

Part of https://github.com/flutter/flutter/issues/145009
https://dart.googlesource.com/external/github.com/flutter/flutter/+/26e5352eecc5990b53afd3e3e0230160883e82ba

DEPS

diff --git a/DEPS b/DEPS
index 0ab0bff..321b634 100644
--- a/DEPS
+++ b/DEPS
@@ -284,7 +284,7 @@
 
   'engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + '58e6149a987155f61877490777d4218015b58a15',
 
-  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '0e633a10b103a631cd42f2a34ce0e3f37dde2d33',
+  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '26e5352eecc5990b53afd3e3e0230160883e82ba',
 
   'engine/src/flutter/third_party/depot_tools':
   Var('chromium_git') + '/chromium/tools/depot_tools.git' + '@' + '580b4ff3f5cd0dcaa2eacda28cefe0f45320e8f7',

commits.json

diff --git a/commits.json b/commits.json
index ffd0a53..802f673 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "engine/src/flutter":"9eed3ce378eca49edd1f591e963165f3074188c0",
   "engine/src/flutter/third_party/dart":"58e6149a987155f61877490777d4218015b58a15",
-  "flutter":"0e633a10b103a631cd42f2a34ce0e3f37dde2d33"
+  "flutter":"26e5352eecc5990b53afd3e3e0230160883e82ba"
 }
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