feat: add the MeshCentral project

[DaanSelen]

Thank you for taking the time to work on a PR for Awesome-Sysadmin!

To ensure your PR is dealt with swiftly please check the following:

• Your additions are Free software
• Software you are submitting is not your own, unless you have a healthy ecosystem with a few contributors (which aren't your sock puppet accounts).
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• Format your submission as follows, where Demo and Clients are optional.
  Source Code, Clients) License Language ``
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Please take some time to answer the following questions as best you can:

• Why is it awesome?

Because this project is open source RMM with an active community which is making it better! Also its very fast!

• Have you used it? For how long?

About 2 years now, production and hobby/at home

• Is this in a personal or professional setup?

Both

• How many devices/users/services/... do you manage with it?

Right now about 110

• Biggest pros/cons compared to other solutions?

The UI might look a bit dated and support can be a bit slow (when there is no funding)

• Any other comments about your use case, things you've found excellent, limitations you've encountered... ?