[airflow] branch v2-1-stable updated (2b50201 -> 13a1533)

[as...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

ash pushed a change to branch v2-1-stable
in repository https://gitbox.apache.org/repos/asf/airflow.git.


    omit 2b50201  Update default versions v2-1-test in the 2.1 branch
     add ed35818  Fix docs spelling errors (#15884)
     add 31894fa  Update installation page (#15737)
     add 13a1533  Update default versions v2-1-test in the 2.1 branch

This update added new revisions after undoing existing revisions.
That is to say, some revisions that were in the old version of the
branch are not in the new version.  This situation occurs
when a user --force pushes a change and generates a repository
containing something like this:

 * -- * -- B -- O -- O -- O   (2b50201)
            \
             N -- N -- N   refs/heads/v2-1-stable (13a1533)

You should already have received notification emails for all of the O
revisions, and so the following emails describe only the N revisions
from the common base, B.

Any revisions marked "omit" are not gone; other references still
refer to them.  Any revisions marked "discard" are gone forever.

No new revisions were added by this update.

Summary of changes:
 docs/apache-airflow/installation.rst        | 48 +++++++++++++++++++++--------
 docs/conf.py                                |  5 ++-
 docs/exts/extra_files_with_substitutions.py | 19 +++++++++---
 docs/spelling_wordlist.txt                  |  2 ++
 4 files changed, 56 insertions(+), 18 deletions(-)