Add new environment variable info to readme.

README.md

@@ -120,7 +120,7 @@ Elasticsearch is no longer supported.
 We recommend that you run Opensearch with docker using the following docker commands:
 
 ```sh
-docker run --name opensearch -d --rm -p 9006:9200 -e "discovery.type=single-node" -e "plugins.security.disabled=true" "opensearchproject/opensearch:1"
+docker run --name opensearch -d --rm -p 9200:9200 -e "discovery.type=single-node" -e "plugins.security.disabled=true" "opensearchproject/opensearch:1"
 docker exec opensearch opensearch-plugin -s install analysis-icu
 docker restart opensearch
 ```
@@ -161,6 +161,14 @@ To let the application know which database to use, set the `SIMPLIFIED_PRODUCTIO
 export SIMPLIFIED_PRODUCTION_DATABASE="postgresql://palace:test@localhost:5432/circ"
 ```
 
+#### Opensearch
+
+To let the application know which Opensearch instance to use, set the `PALACE_SEARCH_URL` environment variable.
+
+```sh
+export PALACE_SEARCH_URL="http://localhost:9200"
+```
+
 #### Storage Service
 
 The application optionally uses a s3 compatible storage service to store files. To configure the application to use
@@ -642,7 +650,7 @@ If you already have elastic search or postgres running locally, you can run them
 following environment variables:
 
 - `SIMPLIFIED_TEST_DATABASE`
-- `SIMPLIFIED_TEST_OPENSEARCH`
+- `PALACE_TEST_SEARCH_URL`
 
 Make sure the ports and usernames are updated to reflect the local configuration.