ci: add netlify.toml with build ignore

[Roshanjossey]

only build on netlify when there is a change in src directory

[codecov[bot]]

Codecov Report

Merging #177 (8d07921) into master (f30ea42) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #177   +/-   ##
=======================================
  Coverage   33.16%   33.16%           
=======================================
  Files         134      134           
  Lines        2192     2192           
  Branches      370      371    +1     
=======================================
  Hits          727      727           
+ Misses       1464     1461    -3     
- Partials        1        4    +3     

Impacted Files	Coverage Δ
src/withTracker.tsx	0.00% <0.00%> (ø)
src/views/FlowView.tsx	0.00% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update f30ea42...8d07921. Read the comment docs.

[Roshanjossey]