Some updates to Lighthouse book (#6995)

* #6447


  - Move some deprecated pages to a new section under `Archived`

- Remove fallback log in mev as the log will not be present after VC using `/eth/v3/validator/blocks` endpoint by default
- Add warning against using Btrfs file system (thank you @ChosunOne for the report)
- Add data shared by @mcdee  on tree states API queries time
- Rename partial withdrawals to validator sweep to differentiate it from the upcoming execution layer partial withdrawals
- Update NAT API response
- Update docs on IPv6

- Rename .md files to follow a standard prefix section name, e.g., installation_*.md, advanced_*.md
- Standardise .md files using underscore `_` instead of hyphen `-` to be consistent with other files naming conventions.

book/src/validator_manager_api.md

@@ -0,0 +1,39 @@
+# Managing Validators
+
+The `lighthouse validator-manager` uses the [Keymanager API](https://ethereum.github.io/keymanager-APIs/#/) to list, import and delete keystores via the HTTP API. This requires the validator client running with the flag `--http`.
+
+## Delete
+
+The `delete` command deletes one or more validators from the validator client. It will also modify the `validator_definitions.yml` file automatically so there is no manual action required from the user after the delete. To `delete`:
+
+```bash
+lighthouse vm delete --vc-token <API-TOKEN-PATH> --validators pubkey1,pubkey2
+```
+
+Example:
+
+```bash
+lighthouse vm delete --vc-token ~/.lighthouse/mainnet/validators/api-token.txt --validators 0x8885c29b8f88ee9b9a37b480fd4384fed74bda33d85bc8171a904847e65688b6c9bb4362d6597fd30109fb2def6c3ae4,0xa262dae3dcd2b2e280af534effa16bedb27c06f2959e114d53bd2a248ca324a018dc73179899a066149471a94a1bc92f
+```
+
+## Import
+
+The `import` command imports validator keystores generated by the staking-deposit-cli/ethstaker-deposit-cli. To import a validator keystore:
+
+```bash
+lighthouse vm import --vc-token <API-TOKEN-PATH> --keystore-file /path/to/json --password keystore_password
+```
+
+Example:
+
+```
+lighthouse vm import --vc-token ~/.lighthouse/mainnet/validators/api-token.txt --keystore-file keystore.json --password keystore_password
+```
+
+## List
+
+To list the validators running on the validator client:
+
+```bash
+lighthouse vm list --vc-token ~/.lighthouse/mainnet/validators/api-token.txt
+```