command.wasm : add voice assistant example for the Web (#171)

Same as the command-line tool "command", but runs in the browser

Also, added helper script "extra/deploy-wasm.sh" and fixed some timing
constants for the WASM examples.

examples/command/command.cpp

@@ -535,7 +535,7 @@ int main(int argc, char ** argv) {
 
     bool is_running  = true;
     bool have_prompt = false;
-    bool ask_prompt = true;
+    bool ask_prompt  = true;
 
     float prob0 = 0.0f;
     float prob  = 0.0f;