Add formula used for dislike calculation

Added Q: How is the dislike count calculated?

Docs/FAQ.md

@@ -1,11 +1,13 @@
 # Frequently Asked Questions
 ## Before asking a question on GitHub or Discord, please refer to this.
 
+
 ### **1. Where does this extension get the data?**
 A Combination of Google APIs and scraped data.
 
 We save all available data to our DB for it to be available after Google shuts down dislike counts in their API.
 
+
 ### **2. Video dislike count doesn't update**
 Right now video dislikes are cached, and aren't updated very frequenly. Once every 2-3 days, not more often.
 
@@ -17,5 +19,23 @@ The extension collects the video id of the video you are watching, fetches the d
 ### **4. What will happen after the YouTube API stops returning the dislike count?**
 The backend will switch to using a combination of archived dislike stats, estimates extrapolated from extension user data and estimates based on view/like ratios for videos whose dislikes weren't archived and for outdated dislike archives.
 
+### **5. How is the dislike count calculated?**
+
+RYD uses the votes from it's users to extrapolate the dislike count.
+
+- If the video was uploaded after the API was shut down:
+
+  $$ RYD \ \ Dislike \ \ Count = ( { RYD \ \ Users \ \ Like \ \ Count \over RYD \ \ Users \ \ Dislike \ \ Count} ) * Public \ \ Like \ \ Count $$
+
+- If the RYD database somehow had the actual like and dislike count (provided by the uploader or from the archive), the dislike count will be calculated based on both - the users' votes and the archived value. The archived value will have less influence on the final count as it ages.
+
+---
+
+This in video form
+
+[![IReturn YouTube Dislike Explained](https://yt-embed.herokuapp.com/embed?v=GSmmtv-0yYQ)](https://www.youtube.com/watch?v=GSmmtv-0yYQ)
+
+---
+
 ## I have security / privacy concerns
 See [this page](SECURITY-FAQ.md) for more info.