Link to path expansion docs

docs/conf_extlinks.py

@@ -5,6 +5,7 @@
     "pynwb-docs": ("https://pynwb.readthedocs.io/en/stable/%s", "%s"),
     "matnwb-src": ("https://github.com/NeurodataWithoutBorders/matnwb/%s", "%s"),
     "nwb-overview": ("https://nwb-overview.readthedocs.io/en/latest/%s", "%s"),
+    "path-expansion-guide": ("https://neuroconv.readthedocs.io/en/main/user_guide/expand_path.html%s", "%s"),
     "conda-install": (
         "https://docs.conda.io/projects/conda/en/latest/user-guide/install/index.html#regular-installation%s",
         "%s",

docs/tutorials/multiple_sessions.rst

@@ -21,7 +21,7 @@ This page helps you automatically identify source data for multiple subjects / s
 File locations are specified as **format strings** that define source data paths of each selected data format.
 
 .. note::
-    Format strings are one component of NeuroConv's **path expansion language**, which has some nifty features for manually specifying complex paths. Complete documentation of the path expansion feature of NeuroConv can be found **here**.
+    Format strings are one component of NeuroConv's **path expansion language**, which has some nifty features for manually specifying complex paths. Complete documentation of the path expansion feature of NeuroConv can be found :path-expansion-guide:`here <>` .
 
 While you don’t have to specify a format strings for all of the pipeline’s data formats, we’re going to find all of our data here for this tutorial.