There is a great chrome plugin called "Google Input Tools" that you can install on Chrome browser. This gives us the ability to write and share in Samskritam or any devnaagri script based language like Hindi or Marathi. Other options are Gujrati, Tamil etc.
Here, after installation, it will show up as installed.
Now is the time to configure it by invoking
chrome://extensions in the chrome url bar.
Click on Options and select संस्कृतम् (and any other language that you want to select):
Now you will see a downward arrow icon on the right top corner of the browser window. This is the google input extension. Activate it by clicking on it and selecting the language you have installed:
Now you can just go to Facebook or any website and start typing in english, and it will transliterate itself to sanskritam. You can choose between the various options that come up.
This is a cool way to write and share shloks from vedic scriptures on social media.