Improve styling of some shortcode examples

[bobbingwide]

Update oik-custom.css to improve styling in the following areas:
For the [bw_table] shortcode:

• Reduce font-size in shortcode examples
• Reduce width of certain columns displayed de: modified, date
• Use list-style-type: none; for lists in [bw_table]: cloned field

For other shortcode examples:

• Improve styling of bw_code snippet and bw_code example paragraphs
• Reduce font-size for p:lang(HTML)

Note: These changes may only apply to the local development version, until the examples are cloned.