update readme

Author: jonhealy1

README.md

@@ -1,10 +1,14 @@
 # STAC FastAPI Elasticsearch
 
-Elasticsearch backend for stac-fastapi. 
+## Elasticsearch backend for stac-fastapi
+-----
 
-Join our [Gitter](https://gitter.im/stac-fastapi-elasticsearch/community) page
+### Join our [Gitter](https://gitter.im/stac-fastapi-elasticsearch/community) page
 
-For changes, see the [Changelog](CHANGELOG.md).
+### Check out the public Postman documentation [Postman](https://documenter.getpostman.com/view/12888943/2s8ZDSdRHA)
+
+### For changes, see the [Changelog](CHANGELOG.md)
+-----
 
 ## Development Environment Setup
 
@@ -23,14 +27,14 @@ Prior to commit, run:
 ```shell
 pre-commit run --all-files
 ```
-
+-----
 
 ## Building
 
 ```shell
 docker-compose build
 ```
-
+-----
 ## Running API on localhost:8080
 
 ```shell
@@ -55,24 +59,26 @@ curl -X "POST" "http://localhost:8080/collections" \
 }'
 ```
 
-Note: this "Collections Transaction" behavior is not part of the STAC API, but may be soon.
-
+Note: this "Collections Transaction" behavior is not part of the STAC API, but may be soon.  
+   
+------
 ## Testing
 
 ```shell
 make test
 ```
-
+-----
 ## Ingest sample data
 
 ```shell
 make ingest
 ```
-
+-----
 ## Elasticsearch Mappings
 
-Mappings apply to search index, not source. 
-
+Mappings apply to search index, not source.  
+    
+-----
 ## Managing Elasticsearch Indices
 
 This section covers how to create a snapshot repository and then create and restore snapshots with this.