Minor edits per EI suggestion 3: moved local .gitignore into main .gitignore

.gitignore

 ReadMe
 Makefile
 
+# emscripten files
+
+emscripten/*.out
+emscripten/*.pkl
+emscripten/espeakng_data_package.js
+emscripten/glue.*
+emscripten/js/*.js
+!emscripten/demo.html
+!emscripten/Makefile
+!emscripten/demo.js
+!emscripten/espeakng.js
+
 # espeak-ng-data
 
 dictsource/*_extra

emscripten/.gitignore

-*.o
-*.out
-*.pkl
-espeakng_data_package.js
-glue.*
-espeakng.worker.*
-pthread-main.js
-!demo.html
-!Makefile