docs: update readme in preparation of v0.6

[aymanbagabas]

• Git LFS support using both HTTP & SSH
• HTTP authentication through user access tokens
• Collaborators' access level

Todo:

• Add database docs PostgreSQL support/documentation #363

[codecov]

Codecov Report

Merging #360 (2749eea) into main (050a0d1) will decrease coverage by 0.22%.
Report is 30 commits behind head on main.
The diff coverage is 45.26%.

❗ Current head 2749eea differs from pull request most recent head 56a98f7. Consider uploading reports for the commit 56a98f7 to get more accurate results

@@            Coverage Diff             @@
##             main     #360      +/-   ##
==========================================
- Coverage   50.52%   50.31%   -0.22%     
==========================================
  Files         107      133      +26     
  Lines        8209    11272    +3063     
==========================================
+ Hits         4148     5672    +1524     
- Misses       3767     5160    +1393     
- Partials      294      440     +146     

Files Changed	Coverage Δ
git/repo.go	50.69% <ø> (+6.71%)	⬆️
server/access/access.go	64.70% <0.00%> (-26.97%)	⬇️
server/backend/hooks.go	0.00% <0.00%> (ø)
server/config/context.go	85.71% <0.00%> (ø)
server/config/file.go	100.00% <ø> (ø)
server/daemon/daemon.go	48.34% <0.00%> (+1.61%)	⬆️
server/db/errors.go	31.57% <ø> (ø)
server/db/logger.go	37.31% <0.00%> (+12.31%)	⬆️
server/db/migrate/migrate.go	32.53% <0.00%> (ø)
server/git/git.go	26.66% <ø> (ø)
... and 67 more

... and 3 files with indirect coverage changes