Allow regular expressions as keywords

[thomasmerz]

Is your feature request related to a problem? Please describe.
This is related to #38
I'm always frustrated when I have to define many keywords that I could also define with a regex.

Describe the solution you'd like
For example it should be possible to define something like that:

   - location: title
     keywords:
       - 'pi?hole.*adblock*'
     labels:
      - pi-hole
      - adblocking

Describe alternatives you've considered
Alternatives right now are defining many keywords:

   - location: title
     keywords:
       - 'pi-hole'
     labels:
      - pi-hole
      - adblocking
   - location: title
     keywords:
       - 'pihole'
     labels:
      - pi-hole
      - adblocking

Additional context
There's no any other context or screenshots about the feature request here.

[thomasmerz]

@riyadhalnur , did you found some time to have a look at my issue?

[riyadhalnur]

@thomasmerz i won't have time to look into this anytime soon. Please feel free to contribute a PR to add this feature.