Make built files use only ASCII characters

Test Plan: Searched for `[^\x00-\x7f]` in vim and had no results, where there were before.

Reviewers: emily

Reviewed By: emily

Differential Revision: http://phabricator.khanacademy.org/D13459

Makefile

@@ -8,7 +8,7 @@ build/katex.js: katex.js $(wildcard src/*.js)
 	./node_modules/.bin/browserify $< --standalone katex > $@
 
 build/katex.min.js: build/katex.js
-	./node_modules/.bin/uglifyjs --mangle < $< > $@
+	./node_modules/.bin/uglifyjs --mangle --beautify ascii_only=true,beautify=false < $< > $@
 
 build/%.less.css: static/%.less
 	./node_modules/.bin/lessc $< $@

README.md

@@ -18,12 +18,6 @@ Download the built files from [the releases page](https://github.com/khan/katex/
 <script src="/path/to/katex.min.js"></script>
 ```
 
-Specify UTF-8 as your content type:
-
-```html
-<meta charset="utf-8">
-```
-
 Call `katex.render` with a TeX expression and a DOM element to render into:
 
 ```js