Added 23 new exercises with image placeholders

[pranavburnwal]

Note: Yet to add images.

Adding exercises:

• Burpee
• Burpee Box Jump
• Burpee Pull-Up
• Half Burpee
• Burpee Broad Jump
• Jumping Jacks
• Star Jumps
• High Knees
• Butt Kicks
• Double Unders
• Single Unders
• Wall Balls
• Farmer's Walk
• Superman Push-Up
• Typewriter Push-Up
• Archer Push-Up
• Diamond Push-Up
• Dive Bomber Push-Up
• Fingertip Push-Up
• Clapping Push-Up
• Pseudo Planche Push-Up
• Two-Arm Kettlebell Swing
• Hollow Body Hold

[pranavburnwal]

cc @yuhonas

[yuhonas]

LGTM Nice one @pranavburnwal

[arubi9]

looks great!

[yuhonas]

Nice, just looking into the failing build in https://github.com/yuhonas/free-exercise-db/actions/runs/20743748143/job/61561763931?pr=20 it looks like a discrepancy between the checked in dist/exercises.json and the one that is generated using https://github.com/yuhonas/free-exercise-db/blob/main/Makefile#L13

With the magic in the CI pipeline happening here https://github.com/yuhonas/free-exercise-db/blob/main/.github/workflows/ci.yaml#L31-L35 @pranavburnwal