Local installation of dependencies/packages (#3)

for details see #3
commits: 
* preemptively added vite build output to gitignore

* created package.json with ```npm init -y```

* installed bootstrap, bootstrap icons and jsmind with npm
```npm install jsmind bootstrap bootstrap-icons```

* installed vite
ran ```npm install --save-dev vite```
response:
´´´
added 57 packages, and audited 62 packages in 4s

8 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities
´´´

* added main.js with basic mindmap example

* changed index.html to reference the src/main.js
by using vite, we can now import all important recources in the main.js file and only need to reference it in the index.html
also added vite helper functions in the package.json file

* quickly added comments

* moved drag-and-drop-nodes code to an extra file and added default options for creating a mindmap to main.js

* uninstalled jsmind, copied repo to src folder and modified import statements
I essentially reset parts of my "progress" with "npm uninstall jsmind". Nonetheless, i chose to import the code manually since it would allow us to more easily modify it in the future. it also circumvents the problem that the drag and drop functionality has caused before.
I hope this way doesn't cause any compatibility issues.

U can now run
```
npm install
npm run dev
```
to start the dev server. And
```
npm install
npm run build
npm run preview
```
to build and display the built application.

* deleted unused folders
the "js" and "css" folders were created with the project and contain bootstrap code. this was rendered useless with the npm installation of bootstrap.

* installed popperjs and did minor adjustments
installed popperjs dependency for bootstrap downdown menus, Changed licence to MIT and changed language in html to english

Author: iloveskittles82

.gitignore

@@ -104,6 +104,10 @@ dist
 .temp
 .cache
 
+# Build output
+dist/
+.vite/
+
 # vitepress build output
 **/.vitepress/dist