Formulate the goals of this project

[certik]

We should formulate the goals and design guidelines and add them to README and some About page.

First draft:

• Lightweight and fast: must load and run immediately on all major browsers and platforms including phones
• Simple clean looking GUI: just a few buttons, simple looking editor, simple looking output window
• If we add complex features, they should be somehow hidden, whether via a checkbox, or enabled via some magic command in the source code, such as %%show_ast or whatever (to disable warnings, we could do %%lfortran --no-warnings, to trigger fixed form, we could do %%lfortran --fixed-form, etc.
• The goal is not to replace VSCode and other editors, but to complement them. We still want first class support of LFortran/LPython in VSCode, with some extension, etc., but that is a separate project.
• Not to replace JupyterLite: for full featured IDE with cells etc, we would just recommend / host JupyterLite.
• One use case: work as a demo to quickly try out features of LFortran, with a dropdown menu to select examples
• Another use case: to teach programming (Fortran) to newcomers: just write code and click Run
• Beautiful error messages
• Access to help
• Add the ability to easily share links to code snippets (Add the ability to easily share links to code snippets #23)