feat: save game statistics to file

[freimair]

Built upon work of @polarmutex and #103 but on a per-game basis.

Combine that with a bit of gnuplot magic, one can track ones progress visually after creating a symlink to the actual logfile eg.

ln -s ~/.local/share/nvim/VimBeGoodStats_games.log stats.log

and running gnuplot with something like:

set datafile separator ','

myTimeFmt = "%Y-%m-%d %H:%M:%S"
set timefmt myTimeFmt

set title "VimBeGood Stats"
set grid
set tics nomirror
set border 11
set xdata time
set xlabel 'Date/Time'
set xtics format myTimeFmt
set xtics rotate
set ylabel 'Time in Seconds'
set yrange [0:]
set y2label 'Success rate'
set y2range [0:1.1]
set y2tics

plot '<(sed "/words/!d" stats.log)' using (strftime(myTimeFmt, $1)):5:7:8 with errorlines title "words" lt rgb "red", \
	'' using (strftime(myTimeFmt, $1)):4 axis x1y2 with linespoints title "words success rate" lt rgb "red", \
	'<(sed "/ci{/!d" stats.log)' using (strftime(myTimeFmt, $1)):5:7:8 with errorlines title "ci{" lt rgb "blue", \
	'' using (strftime(myTimeFmt, $1)):4 axis x1y2 with linespoints title "ci{ success rate" lt rgb "blue", \
	'<(sed "/relative/!d" stats.log)' using (strftime(myTimeFmt, $1)):5:7:8 with errorlines title "relative" lt rgb "green", \
	'' using (strftime(myTimeFmt, $1)):4 axis x1y2 with linespoints title "relative success rate" lt rgb "green", \
	'<(sed "/hjkl/!d" stats.log)' using (strftime(myTimeFmt, $1)):5:7:8 with errorlines title "hjkl" lt rgb "grey", \
	'' using (strftime(myTimeFmt, $1)):4 axis x1y2 with linespoints title "hjkl success rate" lt rgb "grey", \
	'<(sed "/whackamole/!d" stats.log)' using (strftime(myTimeFmt, $1)):5:7:8 with errorlines title "whackamole" lt rgb "orange", \
	'' using (strftime(myTimeFmt, $1)):4 axis x1y2 with linespoints title "whackamole success rate" lt rgb "orange"