Written the package description and the installation in the README file.

README.md

@@ -1,3 +1,70 @@
-# AmiiboService
+# AmiiboService: Amiibo API service written in Swift
 
-A description of this package.
+This package contains a ready-to-use service that can retrieve data as decoded models/entities from any of the [Amiibo API](https://www.amiiboapi.com) available endpoints.
+
+## Installation
+
+It is possible to add this library in your projects either by explicitly add it as a dependency either in a `Package.swift` file or in your Xcode project.
+
+This package has minimum platform requirements that are important to take into account:
+* *iOS 13.0 or higher*;
+* *macOS 10.15 or higher*;
+* *tvOS 13.0 or higher*;
+* *watchOS 8.0 or higher*;
+
+### Package file
+
+In the intended `Package.swift` file, it is required to add the following dependency:
+
+```swift
+dependencies: [
+    // ...
+    .package(url: "https://github.com/rock-n-code/amiibo-service.git", from: "1.0.0")
+    // ...
+],
+```
+
+Then it is required to add the package to your target, like this:
+
+```swift
+targets: [
+    .target(
+        ...
+        dependencies: [
+            .product(name: "AmiiboService", package: "amiibo-service")
+        ],
+        ...
+    ),
+]
+```
+
+### Xcode 
+
+In an opened Xcode project, it is required to do these steps:
+1. click on your Xcode project file to display *Project* and *Targets*;
+2. select the project under the *Project* section to show the *Info*, *Build Settings* and *Package Dependencies* in the center menu of the screen;
+3. select the *Package Dependencies* to show the defined dependencies of the project;
+4. press on the *+* (plus) button to add dependencies to the project;
+5. enter the URL`https://github.com/rock-n-code/amiibo-service` into the *Search or Enter Package URL* located in the upper right corner;
+6. select the given option;
+7. define the dependency rule (the *Up to Next Major Version* option and the *1.0.0* text are recommended);
+8. select the target to which the dependency will be applied (if required);
+9. wait for the package to be resolved and included in the project;
+10. done!
+ 
+
+### Other considerations
+
+This library is fully supported on Apple platforms only for the time being: *iOS*, *macOS*, *tvOS*, and *watchOS*. Support for other platforms such as *Linux* or *Windows* might be added in the future, depending on the type of changes those platforms require but this needs to be researched first. 
+
+⚠️ Please notice that this library only supports the [Swift Package Manager](https://www.swift.org/package-manager/), and that support for other dependency managers such as *Cocoapods* and *Carthage* is not planned. 
+
+## Usage
+
+This package provides an actor called `AmiiboService` which, after is initialised, is responsible for making requests based on a given filter criteria to the remote API, handling the responses, and decoding the retrieved data into models/entities structs, or throws errors if necessary.
+
+It is needless to say, all the necessary filters, models/entities, and enumerations are also provided in this package. 
+
+## Further documentation
+
+For further information about the API, please refer to the [Amiibo API documentation](https://www.amiiboapi.com/docs/) available online.