Support for Linux

**Background:**
I am a React full stack dev currently working with Grommet UI and would really like to use React Sketchapp for UI/UX. However, I do not have access to an OS X system. Most users are on Windows, OS X and Linux (in that order) but Linux and OS X are less than 10% of all computer users. Windows is closer to 90% but as developers most of us use Linux. Personally I work in Linux for almost everything including desktop and server. I would expect any Node.js based app to be able to run seamlessly across Windows, OS X and Linux the same.

| -------------------------------------------------------------------------------------------------
| **Requesting a new feature**
| -------------------------------------------------------------------------------------------------

**Proposal/Feature-request:**
I would like to request a feature to have the ability to run React Sketch.app on Linux. I feel that most developers will then have access to either OS X and or at least Linux like myself. If not possible with Node directly, I would like to propose an Electron based version.

| -------------------------------------------------------------------------------------------------
| **Reporting a bug or issue (not really a bug, but more of a feature request)**
| -------------------------------------------------------------------------------------------------

**Expected behavior:**
Is to run on Linux following ```npm install``` and then ```npm run render```

**Observed behavior:**
```
git clone https://github.com/airbnb/react-sketchapp.git
```
```
cd react-sketchapp/examples/basic-setup && npm install
```
**Works with no issues as expected**
```
nrydevops@cloudshell:~/react-sketchapp (nrydevops)$ npm run render
npm ERR! missing script: render

npm ERR! A complete log of this run can be found in:
npm ERR! /home/nrydevops/.npm/_logs/2019-12-30T21_17_51_020Z-debug.log
```
additional logging:
```
0 info it worked if it ends with ok
1 verbose cli [ '/usr/bin/node', '/usr/bin/npm', 'run', 'render' ]
2 info using npm@6.13.4
3 info using node@v12.14.0
4 verbose stack Error: missing script: render
4 verbose stack at run (/usr/lib/node_modules/npm/lib/run-script.js:155:19)
4 verbose stack at /usr/lib/node_modules/npm/lib/run-script.js:63:5
4 verbose stack at /usr/lib/node_modules/npm/node_modules/read-package-json/read-json.js:116:5
4 verbose stack at /usr/lib/node_modules/npm/node_modules/read-package-json/read-json.js:436:5
4 verbose stack at checkBinReferences_ (/usr/lib/node_modules/npm/node_modules/read-package-json/read-json.js:391:45)
4 verbose stack at final (/usr/lib/node_modules/npm/node_modules/read-package-json/read-json.js:434:3)
4 verbose stack at then (/usr/lib/node_modules/npm/node_modules/read-package-json/read-json.js:161:5)
4 verbose stack at /usr/lib/node_modules/npm/node_modules/read-package-json/read-json.js:382:12
4 verbose stack at /usr/lib/node_modules/npm/node_modules/graceful-fs/graceful-fs.js:115:16
4 verbose stack at FSReqCallback.readFileAfterClose [as oncomplete] (internal/fs/read_file_context.js:61:3)
5 verbose cwd /home/nrydevops/react-sketchapp
6 verbose Linux 4.19.72+
7 verbose argv "/usr/bin/node" "/usr/bin/npm" "run" "render"
8 verbose node v12.14.0
9 verbose npm v6.13.4
10 error missing script: render
11 verbose exit [ 1, true ]
```

**Sketch version:**
latest as of December 30, 2019

Start in examples/basic-setup and run npm install, then compare the expected npm run render command with the reported missing-script error on Linux. Done means the project has a defined, working Linux path for the requested rendering workflow, with its setup and platform requirements documented.

Written by the indexing model from the issue text.