Prints how many challenges you've solved, your total attempts, and
your current and longest solving streaks.
Value
Invisibly, a list with solved, total_challenges,
attempts, current_streak, and longest_streak.
Examples
old_opt <- options(rgrind.storage_dir = tempdir())
rg_stats()
#>
#> ── Your rgrind Stats ───────────────────────────────────────────────────────────
#> ℹ Challenges solved: 0/10
#> ℹ Total attempts: 0
#> ℹ 🔥 Current streak: 0 days
#> ℹ 🏆 Longest streak: 0 days
options(old_opt)