fix(commandlinehelp): Ignore hidden commands

Do not generate documentation for commands when the option class is marked as hidden

Closes #20

Author: ap0llo

src/MdDocs.CommandLineHelp.Test/Pages/_referenceResults/CommandPageTest.GetDocument_returns_expected_document_for_switch_parameters_02.received.txt

@@ -0,0 +1,32 @@
+# `CommandName` Command
+
+**Application:** [TestApp](../index.md)  
+**Version:** 1.2.3
+
+## Usage
+
+```
+TestApp CommandName --option1|-a
+```
+
+## Parameters
+
+| Name                          | Short Name              | Required | Description                |
+| ----------------------------- | ----------------------- | -------- | -------------------------- |
+| [option1](#option1-parameter) | [a](#option1-parameter) | Yes      | Description of parameter 1 |
+
+### `option1` Parameter
+
+Description of parameter 1
+
+|                |                   |
+| -------------- | ----------------- |
+| Name:          | option1           |
+| Short name:    | a                 |
+| Position:      | *Named parameter* |
+| Required:      | Yes               |
+| Default value: | `False`           |
+
+___
+
+*Documentation generated by [MdDocs](https://github.com/ap0llo/mddocs)*