docs: point the key pair links at the anchors that exist

Two pages linked to `#authorization-key-pair` and `#blockchain-key-pair`,
but those headings declare explicit `{#akp}` and `{#bkp}` anchors, so
both links landed at the top of the page instead of the section. The
build does not catch this: it validates file paths, not fragments.

While there, the Kotlin note in the transaction tutorial called the
64-character key a truncated representation, which now contradicts the
naming used everywhere else. It says which form each example takes.

Signed-off-by: Dmitrii Creed <creeed22@gmail.com>

Author: sorabot

src/getting-started/calling-api-endpoints.md

@@ -22,6 +22,6 @@ For examples of scenarios where FIB API endpoints are being called, check out th
 
 ::: tip NOTE
 
-Certain API requests require the use of either your [**Authorization** key pair](../overview/web-interface.md#authorization-key-pair) or [**Blockchain** key pair](../overview/web-interface.md#blockchain-key-pair).
+Certain API requests require the use of either your [**Authorization** key pair](../overview/web-interface.md#akp) or [**Blockchain** key pair](../overview/web-interface.md#bkp).
 
 :::

src/tutorials-api/signing-transactions.md

@@ -9,7 +9,7 @@ For reference, see any of the following tutorials:
 
 The exact implementation to your system may vary depending on the specific SDK or programming language being used. However, the overall sequence of events to sign a transaction should be the following:
 
-1. Create a `keyPair` object from the public and private keys of the user's [**Blockchain** key pair](../overview/web-interface.md#blockchain-key-pair).
+1. Create a `keyPair` object from the public and private keys of the user's [**Blockchain** key pair](../overview/web-interface.md#bkp).
 2. Retrieve the Hex string of the required transaction.
 3. Decode the retrieved transaction Hex string.
 4. Sign the decoded transaction.
@@ -47,7 +47,8 @@ fun decodeSignEncode(transactionHex: String): String {
     val publicKey = "7fbedb314a9b0c00caef967ac5cabb982ec45da828a0c58a9aafc854f32422ac"
 
     // Example ed25519 private key:
-    // Note: In Kotlin/Java SDK the truncated representation is more common, although you can refer to full ones represented as concatenation of private and public ones in other SDKs
+    // Note: the Kotlin/Java SDK takes the 64-character private key, while the JavaScript and
+    // Python examples below take the 128-character Iroha SDK format, which appends the public key.
     val privateKey = "413b285d1819a6166b0daa762bb6bef2d082cffb9a13ce041cb0fda5e2f06dc3"
 
     // Obtain 'keyPair' from the public and private keys of the 'Blockchain' key pair: