Adding documentation for scaled rank. (#267)

src/contributors/07-ranking-algo.md

@@ -22,15 +22,18 @@ Counterbalances the snowballing effect of votes over time with a logarithmic sca
 
 ```
 Rank = ScaleFactor * log(Max(1, 3 + Score)) / (Time + 2)^Gravity
+Scaled_Rank = Rank / log(2 + Users_Active_Month)
 
 Score = Upvotes - Downvotes
 Time = time since submission (in hours)
 Gravity = Decay gravity, 1.8 is default
+Users_Active_Month = The number of users in a given community who have posted / commented in the last month.
 ```
 
-- Lemmy uses the same `Rank` algorithm above, in two sorts: `Active`, and `Hot`.
+- Lemmy uses the same `Rank` algorithm above, in three sorts: `Active`, `Hot`, and `Scaled`.
   - `Active` uses the post votes, and latest comment time (limited to two days).
   - `Hot` uses the post votes, and the post published time.
+  - `Scaled` is similar to `Hot`, but gives a boost to smaller / less active communities.
 - Use Max(1, score) to make sure all comments are affected by time decay.
 - Add 3 to the score, so that everything that has less than 3 downvotes will seem new. Otherwise all new comments would stay at zero, near the bottom.
 - The sign and abs of the score are necessary for dealing with the log of negative scores.

src/users/03-votes-and-ranking.md

@@ -6,6 +6,7 @@ When browsing the frontpage or a community, you can choose between the following
 
 - **Active** (default): Calculates a rank based on the score and time of the latest comment, with decay over time
 - **Hot**: Like active, but uses time when the post was published
+- **Scaled**: Like hot, but gives a boost to less active communities
 - **New**: Shows most recent posts first
 - **Old**: Shows oldest posts first
 - **Most Comments**: Shows posts with highest number of comments first