add readme for mimic-iv-note

Author: alistairewj

mimic-iv-note/README.md

@@ -0,0 +1,31 @@
+# MIMIC-IV-Note
+
+* [buildmimic](/mimic-iv-note/buildmimic) - Scripts to build MIMIC-IV-Note in various database systems
+    * [postgres](/mimic-iv-note/buildmimic/postgres) - PostgreSQL (v10+)
+    * [duckdb](/mimic-iv-note/buildmimic/duckdb) - DuckDB (serverless, single-file)
+    * [bigquery](/mimic-iv-note/buildmimic/bigquery) - BigQuery schemas
+
+MIMIC-IV-Note contains deidentified free-text clinical notes for patients in MIMIC-IV, including discharge summaries and radiology reports. It is a separate download from MIMIC-IV and is available on [PhysioNet](https://physionet.org/content/mimic-iv-note/).
+
+There are currently no derived concept scripts for MIMIC-IV-Note.
+
+## Building the database
+
+### PostgreSQL
+
+```sh
+psql -d mimiciv -f mimic-iv-note/buildmimic/postgres/create.sql
+psql -d mimiciv -v ON_ERROR_STOP=1 -v mimic_data_dir=<path to mimic-iv-note>/note \
+  -f mimic-iv-note/buildmimic/postgres/load_gz.sql
+```
+
+See the [postgres README](/mimic-iv-note/buildmimic/postgres/README.md) for full details.
+
+### DuckDB
+
+```sh
+cd mimic-iv-note/buildmimic/duckdb
+./import_duckdb.sh <path to mimic-iv-note>
+```
+
+See the [duckdb README](/mimic-iv-note/buildmimic/duckdb/README.md) for full details.