[FR] Code Chunk execution

[jnslr]

Description

Currently i'm using VsCode with the Markdown Preview Enhanced extension.

This allows me to integrate code chunks, meaning code snippets that are automatically executed (when saving) and produce dynamic markdown output.

Having a code execution feature would be great.
Of course in the context of a PWA, this would only be possible for Javascript code.

Example

This allows me to create dynamic calculations, such as this one

``` javascript {cmd="node", hide=true output="markdown" run-on-save=true id="calcs"}
var U = 3; //Voltage in V
var R= 1.5; //Resistance in Ohms

var I = U/R; //Current in Amps
var P = U*I; //Power in W

```

# Calc Test

This shows how dynamic calculations in Markdown can be done.

# The Data
``` javascript {cmd="node", hide output="markdown", run-on-save continue="calcs"}
console.log(
    `|Data|Value|Unit|\n`,
    `| :--: | :--: | :--: |\n`,
    `|U|${U}|V|\n`,
    `|I|${R}|Ω|\n`,
);

```

# Calc Current

The current can be calculeted by


``` javascript {cmd="node", hide output="markdown", run-on-save continue="calcs"}
console.log(
  `$$`,
  `I=\\frac{U}{R}`,
  `=\\frac{${U.toFixed(2)}V}{${R.toFixed(2)}\\Omega}`,
  `=${I.toFixed(2)}A`,
  `$$`,
)
```

# Calc Power

The power can be calculated by 

``` javascript {cmd="node", hide output="markdown", run-on-save continue="calcs"}
console.log(
  `$$`,
  `P= U \\cdot I`,
  `= ${U.toFixed(2)}V \\cdot ${I.toFixed(2)} A`,
  `=${P.toFixed(2)}W`,
  `$$`,
)
```

Which produces the following output, where all the calculations dynamically adapt to the variables specified in the first JS section.