[docs] fix composer docs broken links and format

[esrevi]

Proposed changes

Related issues

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case (coverage and e2e)
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

[esrevi]

this file was missing for some reason, i get that from the former repository docs, to be checked if it is still relevant or remove the security link in the overview

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 30.85%. Comparing base (9e83851) to head (684b454).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #13849      +/-   ##
==========================================
- Coverage   30.85%   30.85%   -0.01%     
==========================================
  Files        2910     2910              
  Lines      192274   192274              
  Branches    39191    39190       -1     
==========================================
- Hits        59328    59325       -3     
- Misses     132946   132949       +3     

Flag	Coverage Δ
opencti	30.85% <ø> (-0.01%)	⬇️
opencti-front	2.46% <ø> (ø)
opencti-graphql	68.23% <ø> (-0.01%)	⬇️

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