In the code, config, and wiki fix all incorrectly used instances of the word "remove"

[terrelsa13]

Describe What You Are Trying To Accomplish And Why:

Clear communication of the difference between remove and delete.

• Removing a media_item only removes the entry from Radarr/Sonarr/etc...
  • The media_item still exists on disk.
• Deleting a media_item completely erases it from the disk.
  • Deleting media_items is ONLY done using the Emby/Jellyfin API.

Example:
This will affect the REMOVE_FILES configuration key. It will now become DELETE_FILES.

A Clear And Concise Description Of What You Want To Happen:

Clear communication of the difference between remove and delete.

• Removing a media_item only removes the entry from Radarr/Sonarr/etc...
  • The media_item still exists on disk.
• Deleting a media_item completely erases it from the disk.
  • Deleting media_items is ONLY done using the Emby/Jellyfin API.

Example:
This will affect the REMOVE_FILES configuration key. It will now become DELETE_FILES.

Describe Alternatives You Have Considered:

Keep it the way it currently is.

Any Additional Information You Think Will Be Useful:

As much as I want to have MUMC automatically update old configuration files; my free time is limited.
This will likely be part of a breaking change during a major revision bump.