Add MySqlDecimal documentation.

Signed-off-by: Bradley Grainger <[email protected]>

Author: bgrainger

docs/content/api/MySqlConnector/MySqlDecimal/ToDouble.md

@@ -4,12 +4,26 @@
 
 namespace MySqlConnector;
 
+/// <summary>
+/// <see cref="MySqlDecimal"/> represents a MySQL <c>DECIMAL</c> value that is too large to fit in a .NET <see cref="decimal"/>.
+/// </summary>
 public readonly struct MySqlDecimal
 {
+	/// <summary>
+	/// Gets the value of this <see cref="MySqlDecimal"/> as a <see cref="decimal"/>.
+	/// </summary>
+	/// <remarks>This method will throw an <see cref="OverflowException"/> if the value is too large to be represented.</remarks>
 	public decimal Value => decimal.Parse(m_value, CultureInfo.InvariantCulture);
 
+	/// <summary>
+	/// Gets the value of this <see cref="MySqlDecimal"/> as a <see cref="double"/>.
+	/// </summary>
+	/// <remarks>The return value may have lost precision.</remarks>
 	public double ToDouble() => double.Parse(m_value, CultureInfo.InvariantCulture);
 
+	/// <summary>
+	/// Gets the original value of this <see cref="MySqlDecimal"/> as a <see cref="string"/>.
+	/// </summary>
 	public override string ToString() => m_value;
 
 	internal MySqlDecimal(string value)