Add instructions how to install yarn

[skbormann]

Hi,
I tried to install and run flowpy with the help of the instructions in the README.md. But at least on the machines (Windows 7 and MacOS) which I tried to run flowpy the yarn-program was always missing.
Can you add instructions on how to install the missing program? It seems that it does not get installed by the python modules in the requirements.txt.
For someone who does have it already installed, it could deter them from trying out flowpy.

[schlerp]

Hey!

Thank you for raising the issue. Yarn is actually a package manager for node js so pip wont install it. When this application hits production it wont be a necessary component so I'm not sure if i want to add it to the documentation. What I can do is make it clearer about the development tools required and update the README.md to be more explicit.

[ashwin100196]

Hi, I am on Windows and I used node to run flowpystudio. You can install the latest version of node from here: https://nodejs.org/en/download/

I followed the following steps:

# verify installation
npm -v

cd flowpystudio

# install node modules
npm install

npm start

I think the install step is missing from the README @schlerp , maybe that can be included and an alternative for using npm instead of yarn.

[schlerp]

Haha very true! I had forgotten the install step. It's a bit of a busy week for me but I'll update the Readme and enrich it with a bit more detail around this.

Yarn/Npm can also build the webapp into a set of static files which fastapi in python can express via its static file functionality. This is ideally how actual releases will work with the build artifacts from yarn/Npm being a part of the python package.

Also I recommend yarn over Npm as in our case they serve the same purpose but yarn is much faster at doing what it needs to do 👌