Link to pip docs

Author: konstin

source/specifications/direct-url-data-structure.rst

@@ -12,7 +12,7 @@ source trees, source distributions and wheels.
 
 At time of writing, it is not formally specified how to merge the parts of this
 file into single URL that can be passed to tools. A common representation is the
-pip URL format, other examples are provided in the
+pip URL format (`VCS Support <pip-vcs-support_>`_), other examples are provided in the
 :ref:`Version specifier specification <version-specifiers>`.
 
 Specification
@@ -397,4 +397,5 @@ History
 
 
 .. _archive-info-hashes: https://discuss.python.org/t/22299
+.. _pip-vcs-support: https://pip.pypa.io/en/stable/topics/vcs-support/
 .. _whatwg-url-standard: https://url.spec.whatwg.org/