Adds readme file for the pdfjs-dist repo.

external/dist/README.md

@@ -0,0 +1,10 @@
+# PDF.js
+
+PDF.js is a Portable Document Format (PDF) library that is built with HTML5.
+Our goal is to create a general-purpose, web standards-based platform for
+parsing and rendering PDFs.
+
+This is a pre-built version of the PDF.js source code. It is automatically
+generated by the build scripts.
+
+See https://github.com/mozilla/pdf.js for learning and contributing.

make.js

@@ -246,6 +246,7 @@ target.dist = function() {
   echo('### Overwriting all files');
   rm('-rf', DIST_DIR + '*');
 
+  cp('-R', ROOT_DIR + 'external/dist/*', DIST_DIR);
   cp('-R', GENERIC_DIR + 'LICENSE', DIST_DIR);
   cp('-R', GENERIC_DIR + 'web/cmaps', DIST_DIR);
   mkdir('-p', DIST_DIR + 'build/');