Removed allowance from Mirror Node and SDK section

Signed-off-by: Michael Heinrichs <netopyr@users.noreply.github.com>

HIP/hip-991.md

@@ -263,7 +263,7 @@ message ConsensusTopicInfo {
 
 To comply with this HIP, the Mirror Node provides the following features:
 
-* Support for querying a topic's allowances and custom fees via REST APIs. This may include listing all accounts that have granted allowances to a particular topic.
+* Support for querying a topic's custom fees via REST APIs.
 * Custom fees should be able to be queried by topic, in the same structure as custom fees exist and can be queried on token entities.
 
 #### REST API changes
@@ -369,13 +369,6 @@ console.log(`Created topic with ID: ${receipt.topicId}`);
 
 [...]
 
-// Set allowance
-const spenderTopicId = new TopicID("0.0.54321")
-transactionResponse = new TopicAllowanceApproveTransaction()
-    .approveHbarAllowance(ownerAccount, spenderTopicId, Hbar.from(100), Hbar.from(2)); // Set owner, topicId, maximum allowance, and max per message
-
-[...]
-
 // Define max custom fee
 const maxCustomFee = new FixedFee()
   .setAmount(100) // a maximum of 100 tokens is paid for submitting the message