[REST] added /rest/block/notxdetails/<hash> into REST-interface.md documentation

doc/REST-interface.md

@@ -11,12 +11,15 @@ Given a transaction hash,
 Returns a transaction, in binary, hex-encoded binary or JSON formats.
 
 `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.
 
 The HTTP request and response are both handled entirely in-memory, thus making maximum memory usage at least 2.66MB (1 MB max block, plus hex encoding) per request.
 
+With the /notxdetails/ option JSON response will only contain the transaction hash instead of the complete transaction details. The option only affects the JSON response.
+
 For full TX query capability, one must enable the transaction index via "txindex=1" command line / configuration option.
 
 Risks