Migrate to React 18 (#69)

# Migrate to React 18.3

## ♻️ Current situation & Problem
The project is currently using React 17, which is now deprecated. As a
result, security updates cannot be applied, and other dependencies also
cannot be added or upgraded since they require React 18 or above.

## ⚙️ Release Notes 

- Migrates the project to React 18.3, which is still supported, and
updates dependencies including react-router, react-dnd,
react-dnd-html5-backend, react-i18next, and typescript.
- Fixes eslint warnings / typescript errors.

### Code of Conduct & Contributing Guidelines 

By submitting creating this pull request, you agree to follow our [Code
of
Conduct](https://github.com/StanfordBDHG/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordBDHG/.github/blob/main/CONTRIBUTING.md):
- [X] I agree to follow the [Code of
Conduct](https://github.com/StanfordBDHG/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordBDHG/.github/blob/main/CONTRIBUTING.md).

.eslintrc.js

@@ -0,0 +1,8 @@
+module.exports = {
+  extends: ['react-app'],
+  plugins: ['jest'],
+  env: {
+    'jest/globals': true
+  },
+  root: true
+}; 

CONTRIBUTORS.md

@@ -0,0 +1,7 @@
+Phoenix Contributors
+=================================
+
+* [Vishnu Ravi](https://github.com/vishnuravi)
+* [Lukas Kollmer](https://github.com/lukaskollmer)
+
+This project was originally forked from https://github.com/helsenorge/structor in August 2022.

README.md

@@ -2,7 +2,7 @@
 
 [![Build and Test](https://github.com/StanfordBDHG/phoenix/actions/workflows/build-and-test.yml/badge.svg)](https://github.com/StanfordBDHG/phoenix/actions/workflows/build-and-test.yml)
 
-A web application that allows you to build healthcare surveys using the [HL7® FHIR® Questionnaire](https://www.hl7.org/fhir/questionnaire.html) international data standard using an interactive, drag-and-drop interface, and export JSON to be used in CardinalKit/Spezi iOS and Android applications to deliver surveys to patients.
+A web application that allows you to build healthcare surveys using the [HL7® FHIR® Questionnaire](https://www.hl7.org/fhir/questionnaire.html) international data standard using an interactive, drag-and-drop interface, and export JSON to be used in [Stanford Spezi](https://github.com/StanfordSpezi) iOS and Android applications to deliver surveys to patients.
 
 <img src="figures/home_screenshot.png" />
 
@@ -16,7 +16,7 @@ A web application that allows you to build healthcare surveys using the [HL7® F
 - Node.js & npm
 
 ## Getting Started
-- To use the application online, visit https://stanfordbdhg.github.io/phoenix
+- To use the application online, visit https://stanfordbdhg.github.io/phoenix.
 
 ## Run for Development
 - First, ensure that Node.js (version 16 or greater) and npm are installed on your system.
@@ -31,33 +31,42 @@ A web application that allows you to build healthcare surveys using the [HL7® F
 - The build files will be found in the `build/` subdirectory. You may deploy these files to the static web hosting service of your choice.
 
 ## Build and Run in Docker
-- First, build the docker image:
-```
-docker build -t phoenix-survey-builder
-```
-- Then, run the docker image:
+
+First, build the Docker image:
+
+```bash
+docker build -t phoenix-survey-builder .
 ```
+
+Then, run the Docker image:
+
+```bash
 docker run -p 8080:80 phoenix-survey-builder
 ```
-(You may substitute `8080` in the command above with a different port of your choice if needed.)
 
-- Open `localhost:8080/phoenix` in your browser to view the application.
+> [!TIP]
+> You may also substitute `8080` in the command above with a different port of your choice.
+
+Open `localhost:8080/phoenix` in your browser to view the application.
 
 ## Deploy to GitHub Pages
+
 The repository contains a GitHub Action that will deploy the application to GitHub pages: [deploy.yml](https://github.com/StanfordBDHG/phoenix/blob/dockerize/.github/workflows/deploy.yml). 
 
 Before using the action:
-- Update `package.json` with the full GitHub pages URL for your repository in the `homepage` key, i.e. `https://username.github.io/repository`.
-- Update the main route path in `src/router/index.tsx` with your repository name:
-```
-<Route path="/YOUR_REPOSITORY_NAME" exact>
-...
+1. Update `package.json` with the full GitHub pages URL for your repository in the `homepage` key, i.e. `https://username.github.io/repository`.
+2. Update the main route path in `src/router/index.tsx` with your repository name:
+
+```typescript
+<Route path="/YOUR_REPOSITORY_NAME" element={
+// remainder of code is unchanged
 ```
 
 ## Contributors & License
-The Phoenix Survey Builder is licensed under the [MIT license](LICENSE).
 
-Phoenix is based on the [Structor](https://github.com/helsenorge/structor) project. We are grateful to the [Helse Norge](https://github.com/helsenorge) team for open-sourcing their work.
+The Phoenix Survey Builder is licensed under the [MIT license](LICENSE). For a full list of contributors, see [CONTRIBUTORS.md](CONTRIBUTORS.md).
+
+Phoenix was originally forked from the [Structor](https://github.com/helsenorge/structor) project in August 2022. We are grateful to the [Helse Norge](https://github.com/helsenorge) team for open-sourcing their work.
 
 ## Disclaimer
 HL7®, and FHIR® are the registered trademarks of Health Level Seven International and their use of these trademarks does not constitute an endorsement by HL7.