Add guidance on punctuation in tables

[julian-cable]

Add the following guidance:

• If all cells in a table column are complete sentences, then end each cell with a period.
• If all cells in a table column are sentence fragments, then do not use a period to end each cell.
• If cells in a table column contain a mixture of complete sentences and sentence fragments, then first consider whether it would be appropriate to make them grammatically parallel (either all complete sentences or all sentence fragments). However, in some cases, such an approach might not work, where tables are complex and include a variety of content, such as lists of strings, variables, IP addresses, descriptions, or states (selected or cleared). In such cases, treat each cell as an individual entry, and either use or omit a closing period depending on whether that cell is a complete sentence.

Provide an example of such a complex table.

[julian-cable]

Table example from David O'Brien:

[julian-cable]

Another example from David: