modify README.md: add some badges (open-source-parsers#1070)

Author: dota17

README.md

@@ -1,6 +1,9 @@
 # JsonCpp
 
 [![badge](https://img.shields.io/badge/conan.io-jsoncpp%2F1.8.0-green.svg?logo=data:image/png;base64%2CiVBORw0KGgoAAAANSUhEUgAAAA4AAAAOCAMAAAAolt3jAAAA1VBMVEUAAABhlctjlstkl8tlmMtlmMxlmcxmmcxnmsxpnMxpnM1qnc1sn85voM91oM11oc1xotB2oc56pNF6pNJ2ptJ8ptJ8ptN9ptN8p9N5qNJ9p9N9p9R8qtOBqdSAqtOAqtR%2BrNSCrNJ/rdWDrNWCsNWCsNaJs9eLs9iRvNuVvdyVv9yXwd2Zwt6axN6dxt%2Bfx%2BChyeGiyuGjyuCjyuGly%2BGlzOKmzOGozuKoz%2BKqz%2BOq0OOv1OWw1OWw1eWx1eWy1uay1%2Baz1%2Baz1%2Bez2Oe02Oe12ee22ujUGwH3AAAAAXRSTlMAQObYZgAAAAFiS0dEAIgFHUgAAAAJcEhZcwAACxMAAAsTAQCanBgAAAAHdElNRQfgBQkREyOxFIh/AAAAiklEQVQI12NgAAMbOwY4sLZ2NtQ1coVKWNvoc/Eq8XDr2wB5Ig62ekza9vaOqpK2TpoMzOxaFtwqZua2Bm4makIM7OzMAjoaCqYuxooSUqJALjs7o4yVpbowvzSUy87KqSwmxQfnsrPISyFzWeWAXCkpMaBVIC4bmCsOdgiUKwh3JojLgAQ4ZCE0AMm2D29tZwe6AAAAAElFTkSuQmCC)](https://bintray.com/theirix/conan-repo/jsoncpp%3Atheirix)
+[![badge](https://img.shields.io/badge/license-MIT-blue)](https://github.com/open-source-parsers/jsoncpp/blob/master/LICENSE)
+[![badge](https://img.shields.io/badge/document-doxygen-brightgreen)](http://open-source-parsers.github.io/jsoncpp-docs/doxygen/index.html)
+
 
 [JSON][json-org] is a lightweight data-interchange format. It can represent
 numbers, strings, ordered sequences of values, and collections of name/value
@@ -49,7 +52,7 @@ https://github.com/open-source-parsers/jsoncpp/wiki/Amalgamated-(Possibly-outdat
 If you are using the [Meson Build System](http://mesonbuild.com), then you can get a wrap file by downloading it from [Meson WrapDB](https://wrapdb.mesonbuild.com/jsoncpp), or simply use `meson wrap install jsoncpp`.
 
 ### Other ways
-If you have trouble, see the Wiki, or post a question as an Issue.
+If you have trouble, see the [Wiki](https://github.com/open-source-parsers/jsoncpp/wiki), or post a question as an Issue.
 
 ## License