update README for 2.x EOL

[dhmlau]

Description

Related to #4180

• Update the LTS schedule
• Update to state 2.x has already reached EOL.

[bajtos]

I am proposing to move the new sentence to "Module Long Term Support Policy" section.

This is what we have now:

## Module Long Term Support Policy

LoopBack 2.x is now in maintenance LTS.

My proposal:

## Module Long Term Support Policy

**LoopBack 2.x has reached end of life in April 2019. It is no longer supported.**

If you prefer to keep the information about 2.x EOL at the top, then I am fine with that too, but please update the sentence "LoopBack 2.x is now on maintenance LTS".

[bajtos]

I think it's even more important to update README in our master branch too, that's the content rendered when people arrive at https://github.com/strongloop/loopback and https://www.npmjs.com/package/loopback

[dhmlau]

@bajtos, thanks for your review.

If you prefer to keep the information about 2.x EOL at the top, then I am fine with that too, but please update the sentence "LoopBack 2.x is now on maintenance LTS".

Thanks. I'll update the sentence above the LTS table as well. I put it at the top because the master branch has it at the top too. :)

I think it's even more important to update README in our master branch too

Yes, I'll do it in a separate PR for master.