README: clarify that we're no longer building .deb and RPM

...and say that we're looking for help.

Relates to #203 (main issue), #197, #202, #212, #227, #236, #237.

README.md

@@ -195,14 +195,9 @@ It's assumed that WireGuard is installed on your system, either via the kernel m
 pacman -S innernet
 ```
 
-### Ubuntu
+### Other Linux Distributions
 
-Fetch the appropriate `.deb` packages from
-https://github.com/tonarino/innernet/releases and install with
-
-```sh
-sudo apt install ./innernet*.deb
-```
+Debian and RPM packages are no longer built in this repository directly. We're looking for volunteers who are able to set up external builds for popular distributions. Please see issue [#203](https://github.com/tonarino/innernet/issues/203).
 
 ### macOS
 
@@ -256,5 +251,3 @@ The resulting binary will be located at `./target/release/innernet`
 1. Run `cargo release [--dry-run] [minor|major|patch|...]` to automatically bump the crates appropriately.
 2. Create a new git tag (ex. `v0.6.0`).
 3. Push (with tags) to the repo.
-
-innernet uses GitHub Actions to automatically produce a debian package for the [releases page](https://github.com/tonarino/innernet/releases).