index 2.log

This is pdfTeX, Version 3.14159265-2.6-1.40.16 (TeX Live 2015) (preloaded format=pdflatex 2015.5.24)  18 MAY 2020 12:54
entering extended mode
 restricted \write18 enabled.
 %&-line parsing enabled.
**index.tex
(./index.tex
LaTeX2e <2015/01/01>
Babel <3.9l> and hyphenation patterns for 79 languages loaded.
! Undefined control sequence.
l.1 \hypertarget
                {r-markdow}{% 
Here is how much of TeX's memory you used:
 4 strings out of 493089
 114 string characters out of 6134842
 53199 words of memory out of 5000000
 3590 multiletter control sequences out of 15000+600000
 3640 words of font info for 14 fonts, out of 8000000 for 9000
 1141 hyphenation exceptions out of 8191
 5i,0n,1p,37b,8s stack positions out of 5000i,500n,10000p,200000b,80000s

!  ==> Fatal error occurred, no output PDF file produced!