Mapping to make it easier to insert a pre-defined signature in emails.

Enable `gf`.

I only use this command in an AODocs context. Today, I decided to change
the path where these temporary files are saved. Since the path now uses
a project-specific path variable, it made sense to move the command into
the project file.

Enable it by default in AODocs paths.

When only a single TODO day entry exists in a file, this function would
fail with a "pattern not found" error because the copy pattern expects
at least two entries in a file. Alter the function so that it also works
when only one entry is present in the file.

When creating a new TODO entry, always use the current date instead of
incrementing the final 'day' segment with <C-a>. That would cause issues
when incrementing from "07" (results in "010" instead of "08" because it
assumes it's in octal), and "08" (results in "9" without a leading zero,
though I'm not sure why).

Make it easier to insert reminder comments to write a JSDoc block.

AODocs JSON uses camel case, so this seems like a sensible default.

Enable `gf` and related commands to work by setting the proper 'path',
and ensuring the `.js` suffix is used on files.

I've been keeping a daily to-do list. Every day, I copy yesterday's
entry and use it as today's with some modifications. Add a mapping to
automate copying the previous day's entry.