add news item

Author: tinatn29

news/amd.rst

@@ -0,0 +1,25 @@
+**Added:**
+
+* Functions to compute amd and pdd in src/diffpy/metrics/amd.py 
+* Tests for amd and pdd functions in tests/test_amd.py
+* Test data (two cif files and pkl files (DataFrames)) in tests/test_data
+
+**Changed:**
+
+* Make pre-commit ignore test_data/ folder (in .pre-commit-config.yaml)
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>