Add changelog

ArgumentParsing.sln

@@ -7,6 +7,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 	ProjectSection(SolutionItems) = preProject
 		.editorconfig = .editorconfig
 		.gitignore = .gitignore
+		CHANGELOG.md = CHANGELOG.md
 		Directory.Build.props = Directory.Build.props
 		LICENSE = LICENSE
 		NuGet.config = NuGet.config

CHANGELOG.md

@@ -0,0 +1,13 @@
+# Changelog
+
+## 0.1.0
+
+Initial release of the library.
+
+### Features:
+- Generation of argument parser methods
+- Generated parsers can parse options, parameters and special commands
+- Options are named value, which syntax follows GNU syntax conventions
+- Parameters are unbound values, which are captured from arguments based on parameters' indices
+- Special commands are parsed when a particular first argument is encountered
+- Default implementation of `--help` and `--version` special commands