update readme

README.md

@@ -1 +1,32 @@
 # TextGrid Utilities
+
+Installation:
+```bash
+$ pip install textgrid-utils
+```
+
+Add (optional) auto-complete for CLI usage:
+```bash
+$ eval "$(register-python-argcomplete merge-and-mark-textgrid-tiers)"
+```
+
+Command line usage:
+```bash
+$ merge-and-mark-textgrid-tiers \
+	  -i trial_data.TextGrid \
+	  -o trial_data_merged.TextGrid \
+	  --tiers Phonological Lexical
+```
+
+
+Library usage:
+
+```python
+from textgrid_utils import merge_and_mark_tiers
+
+merge_and_mark_tiers(
+	tg_file="<path/to/input/file>",
+	output_file="<path/to/output/file>",
+	tiers=('Phonlogical', 'Lexical'))
+```
+