Restore inline sourcepos as experimental.

[kivikakk]

Re: #301 (comment).

[github-actions]

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
./bench.sh ./comrak-7e2c1ba	320.2 ± 2.4	317.4	330.4	2.92 ± 0.03
./bench.sh ./comrak-main	318.9 ± 1.5	316.1	323.2	2.90 ± 0.02
./bench.sh ./pulldown-cmark	109.8 ± 0.7	109.0	112.5	1.00
./bench.sh ./cmark-gfm	117.9 ± 0.5	117.1	119.1	1.07 ± 0.01
./bench.sh ./markdown-it	480.0 ± 14.3	475.0	548.1	4.37 ± 0.13

Run on Fri Jul 12 16:20:20 UTC 2024

[kivikakk]

@digitalmoksha Let me know if this looks good/sufficient for you, and then I'll release it as 0.26.0. :)

[digitalmoksha]

@kivikakk yeah that looks good. Thank you! 🙇 🙇 🙇