add wifi manager esp32 (#414)

* add wifi manager esp32

lib/WiFiManager/.github/CONTRIBUTING.md

@@ -0,0 +1,12 @@
+## Contributing PRs and ISSUES
+
+The development branch is the active branch, no features or bugs will be fixed against master ( hotfixes may be considered ).
+
+Please test against development branch before submitting issues, issues against master will be closed, 
+
+PRs against master may be kept open if provides something useful to other members.
+
+Please open issues before sumbitting PRs against development, as commits might be occuring very frequently.
+
+### Documentation is in progress
+https://github.com/tzapu/WiFiManager/issues/500