Rework and harmonize tagline and descriptions

[marclaporte]

As of now:

"About" section at https://github.com/cypht-org/cypht has:

Cypht: Lightweight Open Source webmail written in PHP and JavaScript

https://github.com/cypht-org has:

Cypht Webmail community
Lightweight Open Source webmail written in PHP and JavaScript

https://github.com/cypht-org/cypht/blob/master/README.md has:

All your E-mail, from all your accounts, in one place. Cypht is not your father's webmail. Unless you are one of my daughters, in which case it is your father's webmail. Cypht is like a news reader, but for E-mail. Cypht does not replace your existing accounts - it combines them into one. And it's also a news reader.

https://packagist.org/packages/jason-munro/cypht (which comes https://github.com/cypht-org/cypht/blob/master/composer.json) has:

Lightweight Open Source webmail written in PHP and JavaScript

https://hub.docker.com/r/sailfrog/cypht-docker has

Lightweight open source webmail application written in PHP and JavaScript

I propose we review all these descriptions:

• To better explain what Cypht is, and how it's different in the ecosystem
• To remove references to Jason's daughters. This is the reference: https://en.wiktionary.org/wiki/not_your_father's which not everyone will understand, and the project has evolved to be a community project. Jason is not active at the moment.
• To have official descriptions of various types and lengths that we can easily re-use. Here is an example from another project: https://tiki.org/Facts
• To correspond to the aspirations of the active community: https://github.com/cypht-org/cypht/issues/1037

What do you think?