create a readme for draft logs - throw an error when skipping bad filenames

Author: archmoj

Diff for: draftlogs/.gitignore

@@ -0,0 +1,22 @@
+## Directory of draft logs to help prepare the upcoming [CHANGELOG](https://github.com/plotly/plotly.js/blob/master/CHANGELOG.md)
+
+It is required that the PR contributors start the filename with a number.
+This number should preferably be the PR number.
+The number of issue they are trying to close could also be used.
+The markdown file should end with one of the followings:
+1. `_fix.md` to propose a bug fix
+2. `_add.md` to propose new features
+3. `_remove.md` to propose a feature removal
+4. `_change.md` to propose a minor/major change
+5. `_deprecate.md` to propose a feature deprecate
+
+### Example filename and content for PR numbered 5546 for adding a new feature
+- filename: `5546_add.md`
+- content:
+```
+ - Add `icicle` trace type [[#5546](https://github.com/plotly/plotly.js/pull/5546)]
+```
+which would render
+ - Add `icicle` trace type [[#5546](https://github.com/plotly/plotly.js/pull/5546)]
+
+> Please start your single-line or multiple lined message with a verb. You could basically use the PR description while providing a link to the PR similar to the above example is appreciated too.

Diff for: draftlogs/README.md

@@ -33,6 +33,7 @@ var all = {
 
 var ENTER = '\n';
 
+var skippedFiles = [];
 for(var i = 0; i < len; i++) {
     var filename = allLogs[i];
     var message = fs.readFileSync(path.join(pathToDraftlogs, filename), { encoding: 'utf-8' }).toString();
@@ -49,6 +50,8 @@ for(var i = 0; i < len; i++) {
         all.Changed.push(message);
     } else if(filename.endsWith('_fix.md')) {
         all.Fixed.push(message);
+    } else {
+        skippedFiles.push(filename);
     }
 }
 
@@ -75,3 +78,9 @@ append('Fixed');
 draftNewChangelog.push(foot);
 
 fs.writeFileSync(pathToChangelog, draftNewChangelog.join(ENTER), { encoding: 'utf-8' });
+
+if(skippedFiles.length) {
+    throw JSON.stringify({
+        'skippedFiles': skippedFiles
+    }, null, 2);
+}