Update readme about dashboard (#437)

README.md

@@ -76,6 +76,7 @@ Please visit [Architecture](https://github.com/lyft/amundsen/blob/master/docs/ar
 Amundsen supports two kinds of "nodes" in its graph today:
 - Tables (from Databases)
 - People (from HR systems)
+- Dashboards
 
 Amundsen can connect to any database that provides `dbapi` or `sql_alchemy` interface (which most DBs provide).
 The databases we see most frequently used in the community are:

mkdocs.yml

@@ -63,7 +63,7 @@ nav:
   - 'User Guide':
     - 'Quick Start': 'installation.md'
     - 'Tutorials':
-        - 'How to index the postgres database metadata': 'tutorials/index-postgres.md'
+        - 'How to index metadata for real life databases': 'tutorials/index-postgres.md'
         - 'How to setup a preview client with Apache Superset': 'tutorials/data-preview-with-superset.md'
         - 'How to setup user profiles': 'tutorials/user-profiles.md'
     - 'Deployment':