added README.md + added new build

README.md

+# Tracim lib
+
+This project is used to centralize generic components that are used either in Tracim and in Tracim's apps.
+
+### For development
+While working on Tracim and on tracim_lib, if you change tracim_lib, for the changes to be effective in Tracim you must:
+- run `$ npm run build` on tracim_lib
+- add the generated dist/tracim_lib.js to git stage
+- commit and push changes to tracim_lib
+- increase version number of tracim_lib (package.json)
+- commit push the new version
+- run `$ npm update tracim_lib` in Tracim to get the new version
+
+#### Alternatively you can (faster for development)
+- create a link of tracim_lib using npm: in tracim_lib `$ npm link`
+- get that link in tracim: in tracim (repo) `$ npm link tracim_lib`
+- in tracim_lib: run `$ npm run build`
+
+now, you only have to rebuild tracim_lib and tracim will update it's tracim_lib dependency automatically
+
+Problem: eslint will parse tracim_lib.js since it will come from another repository.
+
+Solution: you must add `/* eslint-disable */` at the beginning and  `/* eslint-enable */` at the end of tracim_lib.js
+
+To automatize this: build tracim_lib with that command:
+
+`npm run build && echo '/* eslint-disable */' | cat - dist/tracim_lib.js > temp && mv temp dist/tracim_lib.js && printf '\n/* eslint-enable */\n' >> dist/tracim_lib.js`
+
+You can also create an alias for this in your .bashrc