GitHub

Creating/editing

Creating a new file within a new directory

From the location where you want to create a new directory, click the "Create new file" button. In the space for the filename, enter the directory name to create, and add a trailing slash. You will then be presented with a blank editor for your new file. Enter the filename at the top and start editing.

If you simply want to create a new directory, you'll need to create a placeholder file to put into it, and commit it. GitHub doesn't like empty directories.

Moving/Renaming a file

Edit the file.

• Move to a subdirectory of the current location: prepend the filename with "/" and start typing the destination subdirectory name.

• Move to a location "above" the current location: prepend the filename with "../" and start typing the destination directory path.

• Change filename: just change the name and commit.

Demo, which explains this much better:

demonstration

Reference: Moving a file to a new location -- GitHub Help

Reviewing diffs

Filter out whitespace changes

Add ?w=1 to the url. Should work in any type of "Compare" view.

Expand/collapse all files at once

Hold down the Alt key and click on the inverted caret icon in any file header.

After clicking the link for "files changed", you can click on any file in the list and it will auto-expand before jumping to the file.

Reference: Collapse all diffs in a pull request at once