adding a simple instuctions for developers

[djarecka]

it should be merged by #116

I'm using poetry since this is the part of the project

[gemini-code-assist]

Code Review

This pull request rebrands the project to StructSense and introduces a detailed developer guide. Feedback includes linking the CI page in the contribution guidelines, standardizing Python version ranges, lowering the Poetry version requirement for better contributor compatibility, and moving inline comments in the environment variable examples to separate lines to prevent potential parsing errors.

[gemini-code-assist]

It would be helpful to link the "Continuous Integration" text to the project's CI page (e.g., GitHub Actions) so contributors can easily check the status and requirements.

Suggested change

	See the [Developer Guide](DEVELOPER.md) for setup instructions and the Continuous Integration for up-to-date requirements.
	See the [Developer Guide](DEVELOPER.md) for setup instructions and the [Continuous Integration](https://github.com/sensein/structsense/actions) for up-to-date requirements.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 15.48%. Comparing base (c8c9884) to head (44bc4c6).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #117   +/-   ##
=======================================
  Coverage   15.48%   15.48%           
=======================================
  Files          28       28           
  Lines        6850     6850           
=======================================
  Hits         1061     1061           
  Misses       5789     5789           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.