add shell script style guides

Author: archmoj

README.md

@@ -77,45 +77,45 @@ There are two kinds of plotly.js partial bundles:
 2. Custom bundles you can create yourself, if none of the distributed packages meet your needs.
 
 Use the `traces` option to include just the trace types you need.
-```
+```sh
 npm run partial-bundle -- --traces scatter,scattergl,scatter3d
 ```
 Please note that the `scatter` trace is currently included in all bundles and cannot be removed.
 [This behaviour may change in the future](https://github.com/plotly/plotly.js/pull/5535), so we recommend that you explicitly include `scatter` anyway if you need it in your bundle.
 
 By default all transforms are included in the bundle.
 Use the `transforms` option to specify which should be included.
-```
+```sh
 npm run partial-bundle -- --transforms sort,filter
 ```
 
 Or use `transforms none` to exclude them all.
-```
+```sh
 npm run partial-bundle -- --transforms none
 ```
 
 Use the `out` option to change the bundle filename (default `custom`).
 The new bundle will be created in the `dist/` directory and named `plotly-<out>.min.js` or `plotly-<out>.js` if unminified.
-```
+```sh
 npm run partial-bundle -- --out myBundleName
 ```
 
 Use the `unminified` option to disable compression.
-```
+```sh
 npm run partial-bundle -- --unminified
 ```
 
 ### Example illustrating use of different options together
 To create an unminified custom bundle named `myScatters` including `scatter`, `scattergl` and `scatter3d` traces without any transforms:
-```
+```sh
 npm run partial-bundle -- \
     --unminified \
     --out myScatters \
     --traces scatter,scattergl,scatter3d \
     --transforms none
 ```
 Or simply on one line:
-```
+```sh
 npm run partial-bundle -- --unminified --out myScatters --traces scatter,scattergl,scatter3d --transforms none
 ```