Markdown tables are generated without escaping pipe character

[WilliamMast]

When a macro (and variables I guess) has a definition or description containing the pipe character "|", it is not escaped and causes missing text in the public description tables.

For instance, let's consider the following code:

/** Test macro
*/
#define MY_MACRO (A | B)

Doxybook will generate:
| Type | Name | | ---: | :--- | | define | [**MY\_MACRO**](myheader_8h.md#define-my-macro) (A | B)<br>_Test macro._ |

Which shows:

Type	Name
define	MY_MACRO (A

I could fix it locally by adding "|replace()" statements in member_template.py. I could do the same to fix newline being not replaced by <br> by doxybook, causing the rest of the table being displayed in plain text after the table, which may happen when defining global variable.

[Kuba Andrýsek]

Hi, I am developing a new plugin doxygen-snippets to easy generate documentation with Mkdocs. The plugin is based on this doxybook project. I hope, I have fixed many of the older bugs from this project. So, you could try my project, or fix your problem with add one line of code into doxybook:markdown.py -> ret = ret.replace('|', '\|')

Result:

def escape(s: str) -> str:
    ret = s.replace('*', '\\*')
    ret = ret.replace('_', '\\_')
    ret = ret.replace('<', '&lt;')
    ret = ret.replace('>', '&gt;')
    ret = ret.replace('|', '\|')
    return ret