update CONTRIBUTING and image-test README

Author: etpinard

CONTRIBUTING.md

@@ -22,47 +22,51 @@ cd plotly.js
 npm install
 ```
 
-**Step 2** Build plotly.js
+**Step 2** Start the test dashboard
 
 ```
-npm run build
+npm run start-test_dashboard
 ```
 
-The build script combines:
+This command bundles up the source files with source maps, starts
+a [watchify](https://github.com/substack/watchify) file watcher (making the your
+dev plotly.js bundle update every time a source file is saved) and opens up
+a tab in your browser.
 
-- `npm run preprocess`, which converts `scss` and `svg` assets to `js` and
-- `npm run bundle`, which runs
-  [browserify](https://github.com/substack/node-browserify) on the source files
+**Step 3** Open up the console and start developing
 
-**Step 3** Start test dashboard
+Make some modification to the source, refresh the page and check the results
+by for example pasting in the console:
 
-```
-npm run start-test_dashboard
+```js
+Plotly.plot(Tabs.fresh(), [{x:[1,2,3], y:[2,1,2]}]);
 ```
 
-This command bundles up the source files with source maps, starts
-[watchify](https://github.com/substack/watchify) file watcher (making the your
-dev plotly.js bundle update every time a source file is saved) and opens up
-a tab in your browser.
+**Other npm scripts**:
+
+- `npm run preprocess`: pre-processes the css and svg source file in js. This
+  script is run automatically on `npm install`.
+- `npm run watch`: starts a watchify file watcher just like the test dashboard but
+  without booting up a server.
+- `npm run lint`: runs jshint on all source files
 
 ### Testing
 
-```
-npm test
-```
+Both jasmine and image test are run on
+[CircleCI](https://circleci.com/gh/plotly/plotly.js) on every pushes to this
+repo.
 
 Jasmine tests are run in a browser using
-[karma](https://github.com/karma-runner/karma)
+[karma](https://github.com/karma-runner/karma). To run them locally:
 
 ```
 npm run test-jasmine
 ```
 
-Image pixel comparison tests are run in a docker container
+Image pixel comparison tests are run in a docker container. For more
+information on how to run them locally, please refer to [image test
+README](https://github.com/plotly/plotly.js/blob/master/test/image/README.md).
 
-```
-npm run test-image
-```
 
 ### Repo organization
 

test/image/README.md

@@ -8,27 +8,28 @@ Test plotly.js with Plotly Image-Server docker container.
 Under your `plotly.js` folder, run
 
 ```bash
-$ docker run -d --name imagetest \
+docker run -d --name imagetest \
     -v $PWD:/var/www/streambed/image_server/plotly.js \
     -p 9010:9010 -p 2022:22 plotly/imageserver:[version]
 ```
 
 where `[version]` is the latest Plotly Image-Server docker container version
 as listed on
-[hub.docker.com](https://hub.docker.com/r/plotly/imageserver/tags/).
+[hub.docker.com](https://hub.docker.com/r/plotly/imageserver/tags/) and
+`imagetest` is the name of the docker container.
 
 ### Run the tests
 
 Under your `plotly.js` folder, run
 
 ```bash
-$ npm run test-image
+npm run test-image
 ```
 
 ### SSH into docker
 
 ```bash
-$ ssh -p 2022 root@localhost # with password `root`
+ssh -p 2022 root@localhost # with password `root`
 ```
 
 If you got this error:
@@ -52,7 +53,7 @@ Host key verification failed.
 simply run
 
 ```bash
-$ ssh-keygen -f "${HOME}/.ssh/known_hosts" -R [localhost]:2022
+ssh-keygen -f "${HOME}/.ssh/known_hosts" -R [localhost]:2022
 ```
 
 to remove host information.