Update README

Author: baseTwo

README.md

@@ -1,13 +1,14 @@
 [![Build Status](https://dev.azure.com/firely/firely-net-sdk/_apis/build/status%2FFirelyTeam.firely-cql-sdk?repoName=FirelyTeam%2Ffirely-cql-sdk&branchName=develop)](https://dev.azure.com/firely/firely-net-sdk/_build/latest?definitionId=143&repoName=FirelyTeam%2Ffirely-cql-sdk&branchName=develop)
 
 
-## Introduction ##
+## Introduction
 This is NCQA's and Firely's official support SDK for working with [CQL][cql-spec] on the Microsoft .NET (dotnet) platform. It contains an engine for executing ELM,
 and/or turning the contents of an ELM file into a .NET assembly so it can be called statically.
 
-## Release notes ##
+## Release notes
 This is release version 2.1 of the engine.
-We expect parts of the public interface can to change. 
+Earlier 1.0 releases will be maintained with hotfixes, but will not receive new features.
+
 The engine has been tested by running it against the current NCQA HEDIS measures and CMS measures.
 There is quite some variation in how CQL is written and interpreted, 
 so it is likely at this early stage that there will be deviations from other engines currently available.
@@ -16,7 +17,7 @@ The releases notes
 at [firely-cql-sdk/releases](https://github.com/FirelyTeam/firely-cql-sdk/releases) for each major version will document these changes and (major) issues we have encountered.
 
 
-## Getting Started ##
+## Getting Started
 
 * Read how to [get started with the Demo solution](docs/getting-started.md) included in the repository.
 * There is a great presentation on the engine from [DevDays 2023](https://youtu.be/CkTbgfbttJc).
@@ -27,7 +28,7 @@ at [firely-cql-sdk/releases](https://github.com/FirelyTeam/firely-cql-sdk/releas
 
 The presentation is a good place to start, but note that we have made some minor changes to the public surface, so the names of the classes in the presentation will differ from the examples in the Demo project itself.
 
-## Dependencies ##
+## Dependencies
 
 The SDK has dependencies on the following key external packages:
 
@@ -87,7 +88,7 @@ Further information can be found in [docs/getting-started.md](docs/getting-start
 ## Support 
 We actively monitor the issues coming in through the GitHub repository at [https://github.com/FirelyTeam/firely-cql-sdk/issues](https://github.com/FirelyTeam/firely-cql-sdk/issues). You are welcome to register your bugs and feature suggestions there. For questions and broader discussions, we use the [.NET FHIR Implementers chat][netsdk-zulip] and [CQL chat][cql-spec] on Zulip.
 
-## Contributing ##
+## Contributing
 We are welcoming contributions!
 
 If you want to participate in this project, we're using [Git Flow][nvie] for our branch management. Please submit PRs with changes against the `develop` branch.