Docs are generated for Mongoose

Comments in headers are changed a bit: removed adoc-specific stuff,
markdown is used instead

PUBLISHED_FROM=9242cce85cc52a47a197d377e7e23804721a6bb5

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

@@ -0,0 +1,13 @@
+---
+title: "mg_send_websocket_framev()"
+decl_name: "mg_send_websocket_framev"
+symbol_kind: "func"
+signature: |
+  void mg_send_websocket_framev(struct mg_connection *nc, int op_and_flags,
+                                const struct mg_str *strings, int num_strings);
+---
+
+Send multiple websocket frames.
+
+Like `mg_send_websocket_frame()`, but composes a frame from multiple buffers. 
+