refact: add 3 SEC issues & enhance the intro/perf doc (#358)

* refact: add 3 SEC issues & enhance the intro/perf doc

also add the .editorconfig for devs

* Remove extra # in h6

* Update hugegraph-benchmark-0.5.6.md 329c566b725776efd46c02ff61fc6fac65ff6091
205 files changed