Update mg_send_websocket_handshake.md

docs/c-api/http.h/mg_send_websocket_handshake.md

@@ -7,14 +7,14 @@ signature: |
                                    const char *extra_headers);
 ---
 
-Send websocket handshake to the server.
+Sends WebSocket handshake to the server.
 
 `nc` must be a valid connection, connected to a server. `uri` is an URI
-to fetch, extra_headers` is extra HTTP headers to send or `NULL`.
+to fetch, `extra_headers` are extra HTTP headers to send or `NULL`.
 
-This function is intended to be used by websocket client.
+This function is intended to be used by the WebSocket client.
 
-Note that the Host header is mandatory in HTTP/1.1 and must be
+Note that the host header is mandatory in HTTP/1.1 and must be
 included in `extra_headers`. `mg_send_websocket_handshake2` offers
 a better API for that.