Update Documentation for installing in Linux to use this repository

[NZSmartie]

Was following the instructions on https://mynewt.apache.org/latest/newt/install/newt_linux/ and found that these two sections point to debian-package:

Add the repository for the binary and source packages to the mynewt.list apt source list file.

$sudo -s
[sudo] password for <user>:
root$ cat > /etc/apt/sources.list.d/mynewt.list <<EOF
deb https://raw.githubusercontent.com/runtimeco/debian-package/master latest main
deb-src https://raw.githubusercontent.com/runtimeco/debian-package/master latest main
EOF
root$exit

and

Verify the content of the source list file:

$more /etc/apt/sources.list.d/mynewt.list
deb https://raw.githubusercontent.com/runtimeco/debian-package/master latest main
deb-src https://raw.githubusercontent.com/runtimeco/debian-package/master latest main

Even though the rest of the documentation lists debian-mynewt. Considering these two sections are used to set up the apt repositories, it's critical these are addressed.

Cheers
Roman