adopt main terminology in the configs

ref pytest-dev/meta#8

doc/en/development_guide.rst

@@ -4,4 +4,4 @@ Development Guide
 
 The contributing guidelines are to be found :ref:`here <contributing>`.
 The release procedure for pytest is documented on
-`GitHub <https://github.com/pytest-dev/pytest/blob/master/RELEASING.rst>`_.
+`GitHub <https://github.com/pytest-dev/pytest/blob/main/RELEASING.rst>`_.

doc/en/funcarg_compare.rst

@@ -168,7 +168,7 @@ pytest for a long time offered a pytest_configure and a pytest_sessionstart
 hook which are often used to setup global resources.  This suffers from
 several problems:
 
-1. in distributed testing the master process would setup test resources
+1. in distributed testing the managing process would setup test resources
    that are never needed because it only co-ordinates the test run
    activities of the worker processes.
 

doc/en/index.rst

@@ -129,8 +129,8 @@ Tidelift will coordinate the fix and disclosure.
 License
 -------
 
-Copyright Holger Krekel and others, 2004-2020.
+Copyright Holger Krekel and others, 2004-2021.
 
 Distributed under the terms of the `MIT`_ license, pytest is free and open source software.
 
-.. _`MIT`: https://github.com/pytest-dev/pytest/blob/master/LICENSE
+.. _`MIT`: https://github.com/pytest-dev/pytest/blob/main/LICENSE

doc/en/license.rst

@@ -29,4 +29,4 @@ Distributed under the terms of the `MIT`_ license, pytest is free and open sourc
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     SOFTWARE.
 
-.. _`MIT`: https://github.com/pytest-dev/pytest/blob/master/LICENSE
+.. _`MIT`: https://github.com/pytest-dev/pytest/blob/main/LICENSE