[WIP] Add install/build instructions in readme

[hsbasu]

This PR fixes and closes the following issues:

1. Please provide instructions on how to compile for other distros Please provide instructions on how to compile for other distros  #96
2. How can I build this software How can I build this software #102

Tested on:

1. Ubuntu Mate 20.04.2
2. Ubuntu 20.10
3. Ubuntu 21.04

closes #96, closes #102

[clefebvre]

You can use dpkg-checkbuilddeps instead of listing dependencies..

I would also suggest to stick to that and dpkg-buildpackage for Debian, and use alternative option only for other distros.

[hsbasu]

I never used it. Let me go through the usage of dpkg-checkbuilddeps. I'll update it accordingly. I provided the dependency list separately to help install on other distros.

You can use dpkg-checkbuilddeps instead of listing dependencies..

Do you mean creating two separate sections like the following?
For Debian based: use dpkg-checkbuilddeps to check and install dependencies, and then build and install using dpkg-buildpackage and remove the manual installation from debian section.
For others:
Use manual method
Because, other distros anyway needs fully manual installation.

I would also suggest to stick to that and dpkg-buildpackage for Debian, and use alternative option only for other distros.

NB: Personally, I would prefer the readme of a GUI app to be more like this. But this might be overkill for many.

Update: I checked the dpkg-checkbuilddeps. It does nothing but showing build dependencies and does not install them. If I am targeting novice users, I think it would be better to keep a separate list of dependencies and a corresponding install instructions.

I would update this PR. Please review it.