docs: add v0.2.1 to CHANGELOG.md

a patch applied to v0.2 that was never tagged until now

CHANGELOG.md

@@ -1,13 +1,17 @@
-# CCBR_tobias development version
+## CCBR_tobias development version
 
 - Fix wildcard not found error. (#10, @kelly-sovacool)
 
-# CCBR_tobias 0.3.0
+## CCBR_tobias 0.3.0
 
-- Update Biowulf module versions in driver script and snakemake config. (#4, @kelly-sovacool)
 - New feature: run `TOBIAS CreateNetwork` to identify TF-TF regulatory networks. (#8, @kelly-sovacool)
 - Add hg19 to the config file for biowulf users. (#8, @kelly-sovacool)
 
-# CCBR_tobias 0.2.0
+## CCBR_tobias 0.2.1
+
+- Update Biowulf module versions in driver script and snakemake config. (#4, @kelly-sovacool)
+
+## CCBR_tobias 0.2.0
 
-Release notes were not written for this version or prior.
+This version corresponds to tag `v0.2`, which did not specify the patch number.
+Release notes were not written for this version or prior.