chore(docs): fix typos in documentation

Pull-Request: #5744.

Author: Pricstas

docs/coding-guidelines.md

@@ -236,7 +236,7 @@ Concurrency adds complexity. Concurrency adds overhead due to synchronization.
 Thus unless proven to be a bottleneck, don't make things concurrent. As an example
 the hierarchical `NetworkBehaviour` state machine runs sequentially. It is easy
 to debug as it runs sequentially. Thus far there has been no proof that
-shows a speed up when running it concurrently.
+shows a speed-up when running it concurrently.
 
 ## Use `async/await` for sequential execution only
 

protocols/gossipsub/CHANGELOG.md

@@ -246,7 +246,7 @@
 
 - Move from `open-metrics-client` to `prometheus-client` (see [PR 2442]).
 
-- Emit gossip of all non empty topics (see [PR 2481]).
+- Emit gossip of all non-empty topics (see [PR 2481]).
 
 - Merge NetworkBehaviour's inject_\* paired methods (see [PR 2445]).