removed output files. They are now available through the WG website a… (#90)

* removed output files. They are now available through the WG website at: https://openid.net/wg/sharedsignals/specifications/

* updated README and gitignore files

Author: tulshi

.gitignore

@@ -1,3 +1,5 @@
+*.html
+*.txt
 *.pdf
 *.epub
 .refcache

README.md

@@ -30,3 +30,5 @@ Pay attention to errors generating the files and warnings about the document dat
 In order to run `make` you need to:
 1. install `xml2rfc` which can be done via pip: `pip install xml2rfc`
 1. install `kramdown-rfc` which can be done via Ruby gems: `gem install kramdown-rfc`
+
+**Note** The HTML and TXT files will not be uploaded to the repository. Running make only ensures that changes you made are not breaking the generation of the specifications output.