chore: clean up wording and typo fixes (#7745)

* chore: clean up wording and typo fixes
* chore: ASCII -> alphanumeric in lexer for heredoc marker

modules/caddyhttp/encode/encode.go

@@ -162,7 +162,7 @@ func (enc *Encode) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyh
 
 			// to comply with RFC 9110 section 8.8.3(.3), we modify the Etag when encoding
 			// by appending a hyphen and the encoder name; the problem is, the client will
-			// send back that Etag in a If-None-Match header, but upstream handlers that set
+			// send back that Etag in an If-None-Match header, but upstream handlers that set
 			// the Etag in the first place don't know that we appended to their Etag! so here
 			// we have to strip our addition so the upstream handlers can still honor client
 			// caches without knowing about our changes...
@@ -369,7 +369,7 @@ const sniffLen = 512
 
 // ReadFrom will try to use sendfile to copy from the reader to the response writer.
 // It's only used if the response writer implements io.ReaderFrom and the data can't be compressed.
-// It's based on stdlin http1.1 response writer implementation.
+// It's based on the standard library HTTP/1.1 response writer implementation.
 // https://github.com/golang/go/blob/f4e3ec3dbe3b8e04a058d266adf8e048bab563f2/src/net/http/server.go#L586
 func (rw *responseWriter) ReadFrom(r io.Reader) (int64, error) {
 	rf, ok := rw.ResponseWriter.(io.ReaderFrom)