[DOCS] Replacing File io image containing Typo with Correct one in sem1/c/ch6

[codingtheself]

Description

In Semester 1, C programming subject, Chapter 6 (https://opencse.vercel.app/sem1/c/ch6).

the first image of File I/O has spelling mistake in the diagram for fopen() and fclose() words but it is written fopon() and flcoso()

screenshot:

Suggested Changes

I would replace that image with the new one with proper spelling for fopen and fclose

[Shravani-36]

I would like to work on this issue