Generator-jhipster: V5 documentation updates

[deepu105]

For v5 we need to update the below documentation compulsory before release.

• [x] Removal of AngularJS to blueprint
• [x] React support
• [x] Blueprint support
• [x] Spring boot 2 updates
• [ ] Angular folder structure updates
• [x] JDL app generation syntax
• [x] Removal of module sub gen
• [ ] Prettier support
• [ ] Oidc updates
• [ ] Add an option [--skip-check-length-of-identifier] to skip check of the length of identifier when generating entity
• [x] Update how to use Gatling
• [x] How to use Memcached
• [x] Embedded elasticsearch is not available starting from v5 hence better to mention the alternative available ways.

We could also use this ticket to draft the changelogs. Wdyt @jdubois
@jhipster/developers plz include if I have missed anything

[gmarziou]

Can we create a v5 branch on https://github.com/jhipster/jhipster.github.io?

[jdubois]

Yes, there's a lot to do here!

[jdubois]

I forgot about this one -- this is mostly done, I'm going to tick some boxes, and then we should probably close it

[pascalgrimaud]

I'm adding Gatling to the list: https://www.jhipster.tech/running-tests/

[pmverma]

Embedded elasticsearch is not available starting from v5 hence better to mention the alternative available ways.

[jdubois]

Not sure if everything is done, but v5 is out for some time and the current documentation is good enough for me, let's close this