docs: fix grammar and typos in comments and documentation (#5254)

* docs: fix grammar and typos in comments and documentation

* docs: use British English style for e.g. and i.e. (no trailing comma)
Changed from American English style (e.g.,) to British English style (e.g.)
for consistency with the rest of the codebase."

packages/fullstack/src/payloads/stream.rs

@@ -89,7 +89,7 @@ pub type ChunkedTextStream = Streaming<String, CborEncoding>;
 /// ## Browser Support for Streaming Input
 ///
 /// Browser fetch requests do not currently support full request duplexing, which
-/// means that that they do not begin handling responses until the full request has been sent.
+/// means that they do not begin handling responses until the full request has been sent.
 ///
 /// This means that if you use a streaming input encoding, the input stream needs to
 /// end before the output will begin.