Update conda_forge_yml.rst (#1404)

Author: ForgottenProgramme

src/maintainer/conda_forge_yml.rst

@@ -24,6 +24,7 @@ Top-level fields
 * :ref:`appveyor`
 * :ref:`azure-config`
 * :ref:`build_platform`
+* :ref:`build_with_mamba`
 * :ref:`bot`
 * :ref:`channel_priority`
 * :ref:`channels`
@@ -134,7 +135,18 @@ build platform using cross-compiling.
 
     build_platform:
       osx_64: linux_64
+      
+.. _build_with_mamba:
 
+build_with_mamba
+--------------
+This option, when enabled, configures the conda-forge CI to run a debug build using the ``mamba`` solver. Check `this <https://conda-forge.org/docs/maintainer/maintainer_faq.html#mfaq-mamba-local>`__ to know more.  
+
+.. code-block:: yaml
+
+    build_with_mamba:
+      True   
+          
 .. _channel_priority:
 
 channel_priority