Minor improvements (#152)

* adjust .gitignore to align with the git repository name

* convert to markdown headline syntax

* fix link to spec in README.adoc

.gitignore

@@ -1,4 +1,5 @@
 /.idea/
 /.vscode/
 /uprotocol-spec.iml
+/up-spec.iml
 /up-core-api/target/

NOTICE.md

@@ -1,21 +1,21 @@
-= Notices for Eclipse uProtocol
+# Notices for Eclipse uProtocol
 
 This content is produced and maintained by the Eclipse uProtocol project.
 
 * Project home: https://projects.eclipse.org/projects/automotive.uprotocol
 
-== Trademarks
+## Trademarks
 
 Eclipse uProtocol is trademark of the Eclipse Foundation.
 Eclipse, and the Eclipse Logo are registered trademarks of the Eclipse Foundation.
 
-== Copyright
+## Copyright
 
 All content is the property of the respective authors or their employers.
 For more information regarding authorship of content, please consult the
 listed source code repository logs.
 
-== Declared Project Licenses
+## Declared Project Licenses
 
 This program and the accompanying materials are made available under the
 terms of the or the Apache License, Version 2.0

README.adoc

@@ -100,7 +100,7 @@ Core uEs are business layer logic to perform a specific function of the protocol
 |link:up-l3/udiscovery/v3/README.adoc[*uDiscovery*]
 |Discovery (services, devices, topics, methods, properties, etc...)
 
-|link:up-l3/utwin/v1/README.adoc[*uTwin*]
+|link:up-l3/utwin/v2/README.adoc[*uTwin*]
 |Local (to the device) caches of published information for subscribed topics
 
 |===