Document that type-feature labels do not need to be paired with version labels (#1259)

Author: erlend-aasland

triage/labels.rst

@@ -26,6 +26,8 @@ These labels are used to specify the type of issue:
 * :gh-label:`type-crash`: for hard crashes of the interpreter, possibly with a
   core dump.
 * :gh-label:`type-feature`: for feature requests or enhancements.
+  Feature requests do not need :ref:`version labels <Version labels>`;
+  it is implicit that features are added to the ``main`` branch only.
   The `Ideas Discourse category`_ can be used to discuss enhancements
   before filing an issue.
 * :gh-label:`type-security`: for security issues.
@@ -81,6 +83,8 @@ You can see the `full list of topic labels on GitHub
 <https://github.com/python/cpython/labels?q=topic>`_.
 
 
+.. _Version labels:
+
 Version labels
 ==============