docs: mention unsupported plugins

[fraziermork]

Please check if the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• [X ] Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• [X ] Other... Please describe: Note added to readme.

What is the current behavior? (You can also link to an open issue here)
Readme does not mention existence of unsupported plugins, see issue #149

What is the new behavior?
Describe which plugins are incompatible

Does this PR introduce a breaking change?

• Yes
• [X ] No

If this PR contains a breaking change, please describe the following...

• Impact:
• Migration path for existing applications:
• Github Issue(s) this is regarding:

Other information:

Add note of which plugins are unsupported based on issue #149

[jsf-clabot]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 5 committers have signed the CLA.

✅ MikaAK
❌ lior-a
❌ eazy-g
❌ DanielaValero
❌ fraziermork

[joshwiens]

@fraziermork - #master is currently being rewritten ( completely ) with the intent of increasing performance and karma-webpack not suffering some the the short comings it does today with the rest of the webpack ecosystem.

Point being, this should really target the v1 branch where this documentation is applicable.

[fraziermork]

@d3viant0ne Is it enough to just change the base branch, or should I close this pull request and make a new one to that branch?

[joshwiens]

You're good with just changing the base branch