Updating roadmap for 2021 (microsoft#1538)

Updating roadmap for 2021

Author: grochocki

docs/Roadmap.md

@@ -4,11 +4,12 @@ Windows Calculator is under active development by Microsoft.
 
 ## Focus
 
-In 2020, the Windows Calculator team is focused on:
-* Iterating upon the existing app design based on the latest guidelines for [Fluent Design](https://developer.microsoft.com/en-us/windows/apps/design), [Windows 10X dual-screen devices](https://docs.microsoft.com/en-us/dual-screen/windows/), and [WinUI 3.0](https://github.com/microsoft/microsoft-ui-xaml).
-* Unblocking community contributions by identifying and addressing bottlenecks affecting developers, including migrating portions of the codebase to C# ([#893](https://github.com/microsoft/calculator/issues/893)) and adding a settings page ([#596](https://github.com/microsoft/calculator/issues/596)).
-* Addressing top user pain points, including clearing up confusion around how Standard Calculator behaves ([#138](https://github.com/microsoft/calculator/issues/138)) and fixing hidden characters in copied results ([#504](https://github.com/microsoft/calculator/issues/504)).
-* Investigating unit converter improvements ([#379](https://github.com/microsoft/calculator/issues/379), [#589](https://github.com/microsoft/calculator/issues/589) and [#594](https://github.com/microsoft/calculator/issues/594))
+In 2021, the Windows Calculator team is focused on:
+* Iterating upon the existing app design based on the latest guidelines for [Fluent Design](https://developer.microsoft.com/en-us/windows/apps/design) and [WinUI](https://github.com/microsoft/microsoft-ui-xaml).
+* Unblocking community contributions by identifying and addressing bottlenecks affecting developers, including:
+  * Migrating the codebase to C# ([#893](https://github.com/microsoft/calculator/issues/893))
+  * Releasing infinite-precision engine as standalone package and adding support for arbitrary expression parsing ([#526](https://github.com/microsoft/calculator/issues/526))
+  * Adding a settings page ([#596](https://github.com/microsoft/calculator/issues/596))
 * [Your feature idea here] - please review our [new feature development process](https://github.com/Microsoft/calculator/blob/master/docs/NewFeatureProcess.md) to get started!
 
 We welcome contributions of all kinds from the community, but especially those that support the efforts above. Please see our [contributing guidelines](https://github.com/Microsoft/calculator/blob/master/CONTRIBUTING.md) for more information on how to get involved.