Add comprehensive XML documentation to critical enumerations

Completes Phase 5 by documenting three critical enumerations with
actual values that users need to know.

Documented enumerations:
- Margins: Added actual inch measurements for None (0"), Default (0.39"),
  Normal (1"), and Large (2")
- DimensionUnitType: Documented all unit types with explanations and
  common use cases (Points, Pixels, Inches, Millimeters, Centimeters, Picas)
- ExtraUrlResourceType: Clarified LinkTag (CSS) vs ScriptTag (JavaScript)
  with HTML tag examples

Key improvements:
- CRITICAL: Users can now see actual margin values in IntelliSense
- Added context for when to use each unit type
- Explained relationship to CSS and HTML tags for extra resources
- All enum values now have clear, concise descriptions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Jaben

src/Gotenberg.Sharp.Api.Client/Domain/Builders/Faceted/Margins.cs

@@ -15,13 +15,28 @@
 
 namespace Gotenberg.Sharp.API.Client.Domain.Builders.Faceted;
 
+/// <summary>
+/// Predefined margin sizes for PDF page properties. All values are in inches.
+/// </summary>
 public enum Margins
 {
+    /// <summary>
+    /// No margins (0 inches on all sides).
+    /// </summary>
     None = 0,
 
+    /// <summary>
+    /// Default margins (0.39 inches on all sides).
+    /// </summary>
     Default = 1,
 
+    /// <summary>
+    /// Normal margins (1 inch on all sides).
+    /// </summary>
     Normal = 2,
 
+    /// <summary>
+    /// Large margins (2 inches on all sides).
+    /// </summary>
     Large = 3
 }

src/Gotenberg.Sharp.Api.Client/Domain/Dimensions/DimensionUnitType.cs

@@ -17,13 +17,39 @@
 
 namespace Gotenberg.Sharp.API.Client.Domain.Dimensions
 {
+    /// <summary>
+    /// Units of measurement for PDF page dimensions and margins.
+    /// </summary>
     public enum DimensionUnitType
     {
-        [Description("pt")] Points, // Points
-        [Description("px")] Pixels, // Pixels
-        [Description("in")] Inches, // Inches
-        [Description("mm")] Millimeters, // Millimeters
-        [Description("cm")] Centimeters, // Centimeters
-        [Description("pc")] Picas // Picas
+        /// <summary>
+        /// Points (1/72 of an inch). Common in typography and print design.
+        /// </summary>
+        [Description("pt")] Points,
+
+        /// <summary>
+        /// Pixels (assumes 96 DPI). Common for screen dimensions.
+        /// </summary>
+        [Description("px")] Pixels,
+
+        /// <summary>
+        /// Inches. Common in US print specifications.
+        /// </summary>
+        [Description("in")] Inches,
+
+        /// <summary>
+        /// Millimeters. Common in international print specifications.
+        /// </summary>
+        [Description("mm")] Millimeters,
+
+        /// <summary>
+        /// Centimeters. Common in international specifications.
+        /// </summary>
+        [Description("cm")] Centimeters,
+
+        /// <summary>
+        /// Picas (1/6 of an inch). Common in typography and print design.
+        /// </summary>
+        [Description("pc")] Picas
     }
 }

src/Gotenberg.Sharp.Api.Client/Domain/Requests/Facets/UrlExtras/ExtraUrlResourceType.cs

@@ -17,12 +17,23 @@
 
 namespace Gotenberg.Sharp.API.Client.Domain.Requests.Facets.UrlExtras;
 
+/// <summary>
+/// Types of external resources that can be injected into URL-based PDF conversions.
+/// </summary>
 public enum ExtraUrlResourceType
 {
-    
+    /// <summary>
+    /// No resource type specified.
+    /// </summary>
     None = 0,
 
+    /// <summary>
+    /// CSS stylesheet injected via link tag (&lt;link rel="stylesheet" href="..."&gt;).
+    /// </summary>
     LinkTag = 1,
 
+    /// <summary>
+    /// JavaScript file injected via script tag (&lt;script src="..."&gt;&lt;/script&gt;).
+    /// </summary>
     ScriptTag = 2
 }