chore: added aliases and started documenting

Tuxedo.Docs/articles/getting-started.md

@@ -9,4 +9,8 @@ this to the top of each `.cs` file that needs it:
 using Tuxedo;
 ```
 
-More to come soon!
+If you're using
+[implicit usings](https://learn.microsoft.com/en-gb/dotnet/core/project-sdk/overview#implicit-using-directives)
+the above is not necessary. This will also import
+many useful aliases, and it is recommended to use them over the full
+names.

Tuxedo.Docs/articles/refinements/numeric/even.md

@@ -0,0 +1,9 @@
+# Even
+
+Enforces that a
+[signed or unsigned numeric type](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/built-in-types)
+is even.
+
+For example,
+
+[!code-csharp[](../../../../Tuxedo.Tests/Numeric/EvenTests.cs#EvenInt)]

Tuxedo.Docs/articles/refinements/numeric/negative.md

@@ -0,0 +1,9 @@
+# Negative
+
+Enforces that a
+[signed or floating point numeric type](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/built-in-types)
+is negative.
+
+For example,
+
+[!code-csharp[](../../../../Tuxedo.Tests/Numeric/NegativeTests.cs#NegativeInt)]

Tuxedo.Docs/articles/refinements/numeric/positive.md

@@ -0,0 +1,9 @@
+# Positive
+
+Enforces that a
+[numeric type](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/built-in-types)
+is positive.
+
+For example,
+
+[!code-csharp[](../../../../Tuxedo.Tests/Numeric/PositiveTests.cs#PositiveInt)]

Tuxedo.Docs/articles/refinements/numeric/toc.yml

@@ -0,0 +1,7 @@
+items:
+  - name: Positive
+    href: positive.md
+  - name: Negative
+    href: negative.md
+  - name: Even
+    href: even.md

Tuxedo.Docs/articles/refinements/toc.yml

@@ -0,0 +1,3 @@
+items:
+  - name: Numeric
+    href: numeric/toc.yml

Tuxedo.Docs/toc.yml

@@ -3,6 +3,8 @@ items:
     href: index.md
   - name: Getting Started
     href: articles/getting-started.md
+  - name: Refinements
+    href: articles/refinements/toc.yml
   - name: .NET API Docs
     href: api/toc.yml
     expanded: true

Tuxedo.Tests/GlobalUsings.cs

@@ -1,4 +1,2 @@
-// Global using directives
-
-global using FluentAssertions;
+global using FluentAssertions;
 global using Xunit;