Update README

[RafaelLiendo]

So, now we support from angular 2 to 9, and the README should reflect that

also, I tried the samples

{{'9999.99' | real}} // output R$9.999,99

and they do not know because you are passing a string as input instead of a number.
so, in some part of the to it tries to

'9999.99'.toFixed(2);
Uncaught TypeError: "9999.99".toFixed is not a function

and it crashes.

And last, with this new version we have 2 README files, one for the project and another for the package. We could mantain them both, but there is probably a better way.

I'm think of something like:
postinstal: "copy README.md, LICENSE, LICENSE.md to dist/ng2-brpipes"