Is your feature request related to a problem? Please describe.
I use the transmission rate limiting feature to limit my download speed, however I find that sometimes I want a rate that is between the preset values on the dropdown menu, but I don't have that option.

Describe the solution you'd like
I'd like to see the ability to use a custom value for download (and upload) speed limits. An example I've seen of this feature is the "limit bandwidth" options in the downloads settings of the Steam games client (picture included for reference).

Describe alternatives you've considered
My ideas are to either replace the dropdown menu with a text input form (same thing as the example with Steam), or adding "custom" as an option on the dropdown menu that will then give a text input form. Anything that allows for custom rate limit values and is shown in the basic settings is welcome.

Additional context
An example implementation of the feature I want, taken from a different piece of software. A text input form for rate limiting with custom values. This screenshot was taken from the Steam games client. In the screenshot, the download rate is limited to the custom value of 800 KB/s.

In comparison, I would not be able to set the same value on Motrix, only 512 KB/s which is lower or 1 MB/s which is higher.