add new yt videos to the docs

[alex-cit]

add https://www.youtube.com/shorts/b9ybh_IgC7o to https://merginmaps.com/docs/field/measure/
add https://www.youtube.com/watch?v=9s3HLOnB4Jo to https://merginmaps.com/docs/field/photo-sketching/
add https://www.youtube.com/watch?v=069-fXNqyJY to https://merginmaps.com/docs/field/mobile-features/#streaming-mode-to-survey-lines-or-areas