updating changelog for v20.11.2 (dgraph-io#7470)

* updating changelog for v20.11.2

* fixing @auth to not become the mention

fix(sort): Fix multi-sort with nils (dgraph-io#7432) (dgraph-io#7444)

Fix the behavior of multi-sort. All the nil values are appended at the end of
the result irrespective of ascending or descending sort. This change also
fixes a bug due to not appending the nil values in the values list,
corresponding to the UIDs appended in the UID list with nil predicates.

(cherry picked from commit 2c7de57)

chore(release): updating code name (dgraph-io#7375)

updating badger (dgraph-io#7357)

fix(sort): Make sort consistent for indexed and without indexed predi…

…cates (dgraph-io#7241) (dgraph-io#7323)

Make the result of sort consistent for predicate with and without index.
After this change, the predicates with null values will appear at the
last of the sort result for both ascending and descending sort, for both
index/no-index case. Before this change the result for predicate with index
didn't contain the null predicates and the one without index treated nulls as
infinite value - they appeared at the beginning for descending while at the
end for the ascending sort case.

NOTE: This is a breaking change for the response of sort.

Co-authored-by: Rajas Vanjape <[email protected]>
(cherry picked from commit 85278f8)

updating codename for v20.07 (dgraph-io#7221)

update changelog for v20.03.7 (dgraph-io#7210)

* update changelog for v20.03

adding changelog for release 20.11 (dgraph-io#7146)

* adding changelog for release 20.11

* fixing duplicates + basic refactor

* fixing changelog with old commit

Update badger (dgraph-io#7136)

Update ristretto to bring in jemalloc-stats fix (dgraph-io#7122)

Use the latest ristretto to bring in the jemalloc-stats fix.

(cherry picked from commit 188711a)