fix link
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Update chapter-1.md
add image
Update chapter-1.md
Update chapter-1.md
add images
Update chapter-1.md
add img
Update chapter-1.md
update chapter-1
update ch1
update ch1
Update chapter-1.md
add img
Update chapter-1.md
add img
Update chapter-1.md
add img
Merge branch 'chapter-1'