Add GFF3 example to quickstart

[cmdcolin]

Ref #1582

Adds a section about loading gff3tabix along with sorting a gff with genometools

Also adds a snippet about loading bigwig and sorting vcf for vcftabix which are carry-overs from #1566 (which is currently stalled)

[codecov]

Codecov Report

Merging #1594 (7d06d3f) into master (415b24a) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1594      +/-   ##
==========================================
- Coverage   59.40%   59.39%   -0.02%     
==========================================
  Files         434      434              
  Lines       19612    19612              
  Branches     4591     4591              
==========================================
- Hits        11651    11649       -2     
- Misses       7667     7669       +2     
  Partials      294      294              

Impacted Files	Coverage Δ
...inearGenomeView/components/RefNameAutocomplete.tsx	86.20% <0.00%> (-3.45%)	⬇️

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