Update assignments.md

[JuhQ]

This pull request includes several typo corrections and minor improvements to the assignments.md file. The changes focus on fixing spelling errors and ensuring consistency in the document.

Typo corrections and consistency improvements:

• Corrected "indivdual" to "individual" in the submission instructions.
• Fixed the formatting of candidate names and initial vote count description.
• Corrected "shoud" to "should" in the voting program instructions.
• Fixed the spelling of "appenChild" to "appendChild" in multiple assignment descriptions. [1] [2]
• Corrected "caption_from_picarray" to "caption_from_picArray" in the HTML example.