Improved the Open API specification document (#19)

This PR contains the work done to improve the `OpenAPI` specification documentation that describes the `Amiibo API` online service as well as updates to the `AmiiboLiveClient` that uses the code generated out of the mentioned document. In addition, some test cases have been updated to reflect the latest data in the service.

Reviewed-on: #19
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Sources/AmiiboService/Catalogs/AmiiboService.docc/Extensions/AmiiboClient.md

@@ -0,0 +1,18 @@
+# ``AmiiboClient``
+
+## Topics
+
+### Amiibo endpoints
+
+- ``AmiiboClient/getAmiibos(by:)``
+- ``AmiiboClient/getAmiiboSeries(by:)``
+- ``AmiiboClient/getAmiiboTypes(by:)``
+
+### Game endpoints
+
+- ``AmiiboClient/getGameCharacters(by:)``
+- ``AmiiboClient/getGameSeries(by:)``
+
+### System endpoints
+
+- ``AmiiboClient/getLastUpdated()``

Sources/AmiiboService/Catalogs/AmiiboService.docc/Extensions/AmiiboLiveClient.md

@@ -0,0 +1,22 @@
+# ``AmiiboLiveClient``
+
+## Topics
+
+### Initializers
+
+- ``AmiiboLiveClient/init(transport:)``
+
+### Amiibo endpoints
+
+- ``AmiiboLiveClient/getAmiibos(by:)``
+- ``AmiiboLiveClient/getAmiiboSeries(by:)``
+- ``AmiiboLiveClient/getAmiiboTypes(by:)``
+
+### Game endpoints
+
+- ``AmiiboLiveClient/getGameCharacters(by:)``
+- ``AmiiboLiveClient/getGameSeries(by:)``
+
+### System endpoints
+
+- ``AmiiboLiveClient/getLastUpdated()``