htmlgen.c libcurl request should be written to a function for code cleanup

[mmertgunduz]

Hello contributor,

htmlgen.c file is a bit complicated and hard to read, we have to make it easier to read.

In order to have that clean code, we have to redo the libcurl request as a function.

File Location: src/mkgen/htmlgen.c

Thanks,
Mehmet Mert