Add strict concurrency checks for Swift 6 support and fix concurrenc…

…y warnings in tests (#130)

* Add checks for Swift 6 support and fix concurrency warnings

* Update .devcontainer/devcontainer.json

Co-authored-by: Tim Gymnich <tim@gymni.ch>

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Co-authored-by: Tim Gymnich <tim@gymni.ch>

Android support (#128)

* Android support

* Add Android CI

* Update Android CI

* Run Android CI on macos-13

* Run Android CI on macos-13

Fix Internal _mantissa problem on Windows (#125)

improve Decimal conversion performance using `_mantissa` (#124)

* improve Decimal conversion performance using `_mantissa`

* fix linux builds by keeping the decimal string init in a compiler directive

* more efficient zero out assurance after buffer creation

* Decimal (from bigint) initializer

Decimal and Foundation (#122)

* add CustomDebugStringConvertible

* reduce Foundation dependency

* if foundation is available, add Decimal functionality

* more concise floating point init

* dry up data initialization

Revert docc related changes from "Migrate from xcworkspace to swift p…

…ackage (#119)"

This reverts the docc related changes in commit 5f01bdc.

fix links

Bumped version