Refactor file and URL paths in docusaurus (#11080)

* Fix introduction link

* Restore staking guide pages

* Remove Edit this page link

* Fix broken wallet guide link

* Restore lost images

* Fixup URL paths to match gitbook style

* Refactor wallet guide READMEs and clean up URLs

* Remove lingering gitbook files

* Refactor all README files to keep consistent linking

* Updte homepage tile links

Co-authored-by: publish-docs.sh <maintainers@solana.com>

docs/src/clusters.md

@@ -57,7 +57,7 @@ The `--trusted-validator`s is operated by Solana
 - Testnet is where we stress test recent release features on a live
   cluster, particularly focused on network performance, stability and validator
   behavior.
-- [Tour de SOL](tour-de-sol/README.md) initiative runs on Testnet, where we
+- [Tour de SOL](tour-de-sol.md) initiative runs on Testnet, where we
   encourage malicious behavior and attacks on the network to help us find and
   squash bugs or network vulnerabilities.
 - Testnet tokens are **not real**