Replace % with f-strings in multiple files mentioned in issue #19

[tusharkhatriofficial]

[Akuli]

You missed one file, basics/modules.md:

basics/modules.md:The `%.2f` rounds to 2 decimals, and you can find more formatting
basics/modules.md:    print("Correct! That took %.2f seconds." % difference)
basics/modules.md:print("You are currently in %s." % os.getcwd())

(this is output from git grep % basics)

[tusharkhatriofficial]

You missed one file, basics/modules.md:

basics/modules.md:The `%.2f` rounds to 2 decimals, and you can find more formatting
basics/modules.md:    print("Correct! That took %.2f seconds." % difference)
basics/modules.md:print("You are currently in %s." % os.getcwd())

(this is output from git grep % basics)

The very last commit you merged was Replace % with f-string in basics/modules.md

[tusharkhatriofficial]

Please review.