add DEVELOP.md

Author: ryan-williams

DEVELOP.md

@@ -0,0 +1,21 @@
+# Regenerate client:
+
+Install desired version of `openapi-generator-cli` ([docs](https://openapi-generator.tech/docs/installation)): 
+```bash
+npm install @openapitools/openapi-generator-cli -g
+openapi-generator-cli version-manager set 7.7.0
+openapi-generator generate -i openapi-v1.yaml -g java
+```
+
+Update local copy of spec from [`TileDB-Server//openapi/v1to3/src/openapi-v1.yaml`](https://github.com/TileDB-Inc/TileDB-Server/blob/main/openapi/v1to3/src/openapi-v1.yaml):
+```bash
+gh api \
+  -H "Accept: application/vnd.github.raw" \
+   /repos/TileDB-Inc/TileDB-Server/contents/openapi/v1to3/src/openapi-v1.yaml \
+> openapi-v1.yaml
+```
+
+Regenerate client:
+```bash
+openapi-generator-cli generate -i openapi-v1.yaml -g java
+```