[Moonlighting] - Add note in section about company compensation programs

[jlprat]

Some companies offer compensation for employees doing OSS contributions during their free time. Document this

[anajsana]

@jlprat in which section will you document this? Maybe contributions-to-existing-projects ?

[anajsana]

And I guess this is a related PR: #44

[jlprat]

I agree, yes it should be under that one

[misappi]

Not required for v1.0. Can be added later.