adds script to update docs ml5 versions (#666)

Author: joeyklee

package.json

@@ -18,6 +18,7 @@
     "test-travis": "./scripts/test-travis.sh",
     "serve:docs": "docsify serve docs",
     "update:readme": "node ./scripts/updateReadme.js",
+    "update:docs": "node ./scripts/updateDocVersions.js $oldversion",
     "publish:npm": "npm run build && npm publish"
   },
   "repository": {

scripts/updateDocVersions.js

@@ -0,0 +1,54 @@
+/**
+ * USAGE
+ * run:
+ *```
+ *$ oldversion=0.4.2 npm run update:docs
+ *```
+ */
+
+const fs = require('fs');
+
+
+// ------------------
+//  Helper functions
+// ------------------
+function readTextFile(fpath){
+  const readme = fs.readFileSync(fpath, 'utf8');
+  return readme;
+}
+
+function readPackageJson(fpath){
+  let output = fs.readFileSync(fpath);
+  output = JSON.parse(output);
+  return output;
+}
+
+function updateFileVersion(inputFilePath, regex, newUrl){
+  const readme = readTextFile(inputFilePath);
+  const updatedReadme = readme.replace(regex, newUrl) 
+  fs.writeFileSync(inputFilePath, updatedReadme);
+}
+
+const oldVersion = process.env.oldversion;
+const ml5Version = readPackageJson('./package.json').version || 'latest';
+const newUrl = `https://unpkg.com/ml5@${ml5Version}/dist/ml5.min.js`;
+const regex = new RegExp(`https://unpkg.com/ml5@${oldVersion}/dist/ml5.min.js`, "g");
+
+
+function make(){
+  if(!oldVersion) {
+    console.log("!!!old version needed!!! \n  oldversion=0.4.X npm run update:docs");
+    process.exit(1);
+  }
+
+  updateFileVersion('./docs/README.md', regex, newUrl);
+  updateFileVersion('./docs/tutorials/hello-ml5.md', regex, newUrl);
+  
+  console.log(`updated docs from version ${oldVersion} to ${ml5Version}`)
+}
+make();
+
+
+
+
+