Migrate links from wiki to notion (#5862)

See the slack discussion:
https://neondb.slack.com/archives/C033A2WE6BZ/p1696429688621489?thread_ts=1695647103.117499

.github/PULL_REQUEST_TEMPLATE/release-pr.md

@@ -3,7 +3,7 @@
 **NB: this PR must be merged only by 'Create a merge commit'!**
 
 ### Checklist when preparing for release
-- [ ] Read or refresh [the release flow guide](https://github.com/neondatabase/cloud/wiki/Release:-general-flow)
+- [ ] Read or refresh [the release flow guide](https://www.notion.so/neondatabase/Release-general-flow-61f2e39fd45d4d14a70c7749604bd70b)
 - [ ] Ask in the [cloud Slack channel](https://neondb.slack.com/archives/C033A2WE6BZ) that you are going to rollout the release. Any blockers?
 - [ ] Does this release contain any db migrations? Destructive ones? What is the rollback plan?
 

docs/rfcs/023-the-state-of-pageserver-tenant-relocation.md

@@ -177,7 +177,7 @@ I e during migration create_branch can be called on old pageserver and newly cre
 
 The difference of simplistic approach from one described above is that it calls ignore on source tenant first and then calls attach on target pageserver. Approach above does it in opposite order thus opening a possibility for race conditions we strive to avoid.
 
-The approach largely follows this guide: <https://github.com/neondatabase/cloud/wiki/Cloud:-Ad-hoc-tenant-relocation>
+The approach largely follows this guide: <https://www.notion.so/neondatabase/Cloud-Ad-hoc-tenant-relocation-f687474f7bfc42269e6214e3acba25c7>
 
 The happy path sequence:
 

scripts/export_import_between_pageservers.py

@@ -18,7 +18,7 @@
 # 6. We wait for the new pageserver's remote_consistent_lsn to catch up
 #
 # For more context on how to use this, see:
-# https://github.com/neondatabase/cloud/wiki/Storage-format-migration
+# https://www.notion.so/neondatabase/Storage-format-migration-9a8eba33ccf8417ea8cf50e6a0c542cf
 
 import argparse
 import os

test_runner/regress/test_compatibility.py

@@ -449,7 +449,7 @@ def check_neon_works(
     )
 
     # Check that project can be recovered from WAL
-    # loosely based on https://github.com/neondatabase/cloud/wiki/Recovery-from-WAL
+    # loosely based on https://www.notion.so/neondatabase/Storage-Recovery-from-WAL-d92c0aac0ebf40df892b938045d7d720
     tenant_id = snapshot_config["default_tenant_id"]
     timeline_id = dict(snapshot_config["branch_name_mappings"]["main"])[tenant_id]
     pageserver_port = snapshot_config["pageservers"][0]["listen_http_addr"].split(":")[-1]