mention the 'bitset' module on planet.gnu.org?

[Bruno Haible]

Hi Akim,

You might have noticed that we are currently publishing a news item per week
about Gnulib in https://savannah.gnu.org/news/?group=gnulib ; they get
propagated to http://planet.gnu.org/ .

Would you want to write a short text about the 'bitset' module, for
publication on 2021-01-06 or 2021-01-20?

The audience is someone who may have heard about Gnulib, but is not yet
using it.

Bruno