fix(qqbot): recognize GFM table separators with one or two dashes (#9… (opens in new tab)

…5637) `isTableSeparatorLine` required 3+ dashes per cell (`/^:?-{3,}:?$/`), but a GFM delimiter cell needs only one or more dashes. So a valid table whose separator used 1 or 2 dashes (e.g. `|--|...