Relax deployment target to macOS 10.15 (#6)

### Motivation

Relax deployment target to macOS 10.15

### Modifications

- Reduced requirement from macOS 13 to macOS 10.15
- Added the minimum version to readme and documentation

### Result

- Users will be able to deploy it on projects with a minimum deployment
target of 10.15

Author: denil-ct

Package.swift

@@ -18,7 +18,7 @@ import PackageDescription
 let package = Package(
     name: "swift-openapi-async-http-client",
     platforms: [
-        .macOS(.v13),
+        .macOS(.v10_15),
     ],
     products: [
         .library(
@@ -29,7 +29,7 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/apple/swift-nio", from: "2.51.0"),
         .package(url: "https://github.com/swift-server/async-http-client.git", from: "1.17.0"),
-        .package(url: "https://github.com/apple/swift-openapi-runtime", .upToNextMinor(from: "0.1.0")),
+        .package(url: "https://github.com/apple/swift-openapi-runtime", .upToNextMinor(from: "0.1.3")),
         .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
     ],
     targets: [

README.md

@@ -4,6 +4,11 @@ A client transport that uses the [HTTPClient](https://swift-server.github.io/asy
 
 Use the transport with client code generated by [Swift OpenAPI Generator](https://github.com/apple/swift-openapi-generator).
 
+## Supported platforms and minimum versions
+ | macOS | Linux |
+ | :-: | :-: |
+ | ✅ 10.15+ | ✅ |
+
 ## Usage
 
 Add the package dependency in your `Package.swift`:

Sources/OpenAPIAsyncHTTPClient/Documentation.docc/Documentation.md

@@ -8,6 +8,11 @@ A client transport that uses the [HTTPClient](https://swift-server.github.io/asy
 
 Use the transport with client code generated by [Swift OpenAPI Generator](https://github.com/apple/swift-openapi-generator).
 
+### Supported platforms and minimum versions
+| macOS | Linux |
+| :-: | :-: |
+| ✅ 10.15+ | ✅ |
+
 ### Usage
 
 Add the package dependency in your `Package.swift`: