`gq` formatoption

Current formatoption for markdown is formatoption=jtln from set formatoptions?

                        *fo-j*

j Where it makes sense, remove a comment leader when joining lines. For example, joining: int i; // the index ~ // in the list ~ Becomes: int i; // the index in the list ~

                        *fo-t*

t Auto-wrap text using ‘textwidth’

                        *fo-l*

l Long lines are not broken in insert mode: When a line was longer than ‘textwidth’ when the insert command started, Vim does not automatically format it.

                        *fo-n*

n When formatting text, recognize numbered lists. This actually uses the ‘formatlistpat’ option, thus any kind of list can be used. The indent of the text after the number is used for the next line. The default is to find a number, optionally followed by ‘.’, ‘:’, ‘)’, ‘]’ or ‘}’. Note that ‘autoindent’ must be set too. Doesn’t work well together with “2”. Example: > 1. the first item wraps 2. the second item