There's a merged pull request on the void-packages repository

fdm: add MANUAL file.
https://github.com/void-linux/void-packages/pull/45850

Description:
Most of the documentation for this program are in the plaintext MANUAL file. If we're including the examples, the MANUAL is just as helpful to have around if not more so.

#### Testing the changes
- I tested the changes in this PR: **YES**


#### Local build testing
- I built this PR locally for my native architecture, x86_64-glibc