Merge bitcoin/bitcoin#24467: doc: minor improvements in getutxos REST endpoint synopsis

c456302 doc: minor improvements in getutxos REST endpoint synopsis (Sebastian Falbesoner)

Pull request description:

  Describing an optional sub-path as `<checkmempool>` in the synopsis could be misleading as the angle brackets normally indicate that the field has to be replaced a custom value. Clarify that by showing two variants instead, similar to the `block` endpoint with the `notxdetails` option:
  ```
  #### Blocks
  `GET /rest/block/<BLOCK-HASH>.<bin|hex|json>`
  `GET /rest/block/notxdetails/<BLOCK-HASH>.<bin|hex|json>`
  ```

  Further improvements:
  - uppercase `<TXID>` and `<N>`, to match the description of the other endpoints
  - s/getutxo command/getutxos endpoint/
  - describe what the `checkmempool` option does
  - s/serialisation/serialization/ (the US spelling is more dominant than the UK spelling in the project, and there is indeed no other instance of the string "serialis*" in the source tree, except once in a release note)
  - link to BIP64 within the text instead of only showing bare URL
  - mention that BIP64 is only relevant for `bin` and `hex` output formats
  - show two endpoint formats of the block section as list

ACKs for top commit:
  stickies-v:
    ACK c456302 - also checked that current master (cc12b89) doesn't have any other lines changes that would require updates as per the outlined improvement points.

Tree-SHA512: b025aac0812397f5fbf78c805c13aeb5afa6862a049d13c0b101178799cdaff1ccd3abc368a5c103ea6ebf17cdff76584c54638d0f8d303d81ade2d71443d305

Author: fanquake

doc/REST-interface.md

@@ -37,8 +37,8 @@ By default, this endpoint will only search the mempool.
 To query for a confirmed transaction, enable the transaction index via "txindex=1" command line / configuration option.
 
 #### Blocks
-`GET /rest/block/<BLOCK-HASH>.<bin|hex|json>`
-`GET /rest/block/notxdetails/<BLOCK-HASH>.<bin|hex|json>`
+- `GET /rest/block/<BLOCK-HASH>.<bin|hex|json>`
+- `GET /rest/block/notxdetails/<BLOCK-HASH>.<bin|hex|json>`
 
 Given a block hash: returns a block, in binary, hex-encoded binary or JSON formats.
 Responds with 404 if the block doesn't exist.
@@ -87,11 +87,13 @@ Only supports JSON as output format.
 Refer to the `getblockchaininfo` RPC help for details.
 
 #### Query UTXO set
-`GET /rest/getutxos/<checkmempool>/<txid>-<n>/<txid>-<n>/.../<txid>-<n>.<bin|hex|json>`
+- `GET /rest/getutxos/<TXID>-<N>/<TXID>-<N>/.../<TXID>-<N>.<bin|hex|json>`
+- `GET /rest/getutxos/checkmempool/<TXID>-<N>/<TXID>-<N>/.../<TXID>-<N>.<bin|hex|json>`
 
-The getutxo command allows querying of the UTXO set given a set of outpoints.
-See BIP64 for input and output serialisation:
-https://github.com/bitcoin/bips/blob/master/bip-0064.mediawiki
+The getutxos endpoint allows querying the UTXO set, given a set of outpoints.
+With the `/checkmempool/` option, the mempool is also taken into account.
+See [BIP64](https://github.com/bitcoin/bips/blob/master/bip-0064.mediawiki) for
+input and output serialization (relevant for `bin` and `hex` output formats).
 
 Example:
 ```