📝 Add developer docs for random state

Ref FCP-INDI/C-PAC#1496

Co-authored-by: Greg Kiar <[email protected]>

Author: shnizzedy

docs/_sources/developer/random_state.rst

@@ -0,0 +1,13 @@
+Random State
+============
+
+When performing reproducibility/variability experiments, it is important to isolate sources of variability. One such source is random state.
+
+Users can fix the random state of C-PAC's execution by specifying a random seed. When adding a Node that should accept a user-specified random seed, add
+
+* the :py:class:`nipype.interfaces.base.core.Interface` and the corresponding flags to add/remove to set the random seed, or
+* in the case of a :py:class:`CPAC.utils.interfaces.function.Function` Node, the Function node's function and a function to apply to that function definition to set the random seed
+
+to :py:function:`CPAC.pipeline.random_state.seed.random_seed_flags`.
+
+.. py:function:: CPAC.pipeline.random_state.seed.random_seed_flags