These new sections look good, but I'd turn them into lists and add an "available algorithms" header. Like this:

```
Available algorithms for linear regression:
* [RidgeRegressionWithSGD](api/mllib/index.html#org.apache.spark.mllib.regression.RidgeRegressionWithSGD)
```

Also, your URLs seem wrong currently because they include backticks. Try clicking them to make sure they go to the right place.