fixup! EDU-2000: Adds vcdiff to JS delta docs

Author: franrob-projects

content/channels/options/deltas.textile

@@ -48,7 +48,7 @@ blang[javascript,nodejs].
 
   h2(#vcdiff). Install vcdiff decoder
 
-  A Vcdiff decoder written in pure JavaScript. The vcdiff decoder is a JavaScript library that decodes delta-compressed messages, allowing clients to reconstruct full messages from the small "diffs" sent by Ably to reduce bandwidth usage.
+  The vcdiff decoder is written in pure JavaScript and enables clients to reconstruct full messages from the small "diffs" sent by Ably.
 
   h3(#install). Installation from npm for Node.js
 
@@ -74,6 +74,15 @@ blang[javascript,nodejs].
   <script src="https://cdn.ably.io/lib/vcdiff-decoder.min-1.js"></script>
   ```
 
+  h3(#exported). Exported functions
+
+  The vcdiff decoder library exports the following function for manual delta decoding.
+
+  @decode(delta, source)@ applies a vcdiff delta to a source message to return a "@Uint8Array@":https://nodejs.org/api/buffer.html#buffer containing the target message:
+
+  * @delta@: The binary delta/diff data.
+  * @source@: The original message to apply the delta to.
+
 blang[default].
 
 h2(#subscribe). Subscribe using delta
@@ -167,19 +176,6 @@ channel.Subscribe(message => {
 });
 ```
 
-  blang[javascript,nodejs].
-
-h3(#exported). Exported functions
-
-The vcdiff decoder library exports the following function for manual delta decoding.
-
-@decode(delta, source)@ applies a vcdiff delta to a source message to return a "@Uint8Array@":https://nodejs.org/api/buffer.html#buffer containing the target message:
-
-* @delta@: The binary delta/diff data.
-* @source@: The original message to apply the delta to.
-
-blang[default].
-
 h2(#limitations). Known limitations
 
 In principle, @vcdiff@ deltas can be applied to encrypted message payloads, but in practice this provides no benefit because there is no similarity between successive encrypted payloads even for identical or near-identical plaintext message payloads.