Add entities source location

Author: dpvc

components/src/source.js

@@ -33,6 +33,7 @@ export const source = {
   '[tex]/unicode': `${src}/input/tex/extensions/unicode/unicode.js`,
   '[tex]/verb': `${src}/input/tex/extensions/verb/verb.js`,
   'input/mml': `${src}/input/mml/mml.js`,
+  'input/mml/entities': `${src}/input/mml/entities/entities.js`,
   'input/asciimath': `${src}/input/asciimath/asciimath.js`,
   'output/chtml': `${src}/output/chtml/chtml.js`,
   'output/chtml/fonts/tex': `${src}/output/chtml/fonts/tex/tex.js`,