xyzEditor: Markdown, LaTeX and AsciiMath Editor

## xyzEditor
A minimalist online [Markdown](https://www.markdownguide.org/), [$\LaTeX$](https://www.latex-project.org/), and [AsciiMath](https://asciimath.org/) Editor.
- **GitHub Flavoured Markdown:** Enables comprehensive Markdown syntax.
- **LaTeX Integration:** Uses [$\KaTeX$](https://katex.org/) for rendering mathematical expressions. Inline maths are enclosed in single dollar signs, e.g. $ax^2 + bx + c = 0$, while display maths use double dollar signs:
$$
x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}
$$
- **AsciiMath Support:** Optionally overrides standard Markdown code behaviour to render inline maths, e.g. `int_-oo^oo e^(-x^2)=sqrt(pi)`. Display maths can be written in fenced code blocks using the info string "am":
```am
sum_(n=1)^oo1/n=prod_p 1/(1-p^-1)
```
- **Mermaid Integration:** Supports diagrams and visualisations using [Mermaid](https://mermaid.js.org/)’s Markdown-inspired text definitions:
```mermaid
graph LR
  A([Guess x₀]) --> B["$$x_{n+1}=x_n-f(x_n)/f'(x_n)$$"]
  B --> C{Converge}
  C -- No --> B
  C -- Yes --> D([Found])
```
- **Enhanced Printing:** Improves browser printing by optionally redefining Markdown horizontal rules, e.g. *** as page breaks, and controlling print margins, page numbering, and title display where supported.

***

- **Theme Support:** Provides multiple rendering themes, including *Default*, *Black & White*, and *GitHub*.

xyzEditor

A minimalist online Markdown, $\LaTeX$ , and AsciiMath Editor.

GitHub Flavoured Markdown: Enables comprehensive Markdown syntax.
LaTeX Integration: Uses $\KaTeX$ for rendering mathematical expressions. Inline maths are enclosed in single dollar signs, e.g. $ax^2 + bx + c = 0$ , while display maths use double dollar signs:

x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}

AsciiMath Support: Optionally overrides standard Markdown code behaviour to render inline maths, e.g. $\int_{- \infty}^{\infty} e^{- x^{2}} = \sqrt{\pi}$ . Display maths can be written in fenced code blocks using the info string "am":

\sum_{n = 1}^{\infty} \frac{1}{n} = \prod_{p} \frac{1}{1 - p^{- 1}}

Mermaid Integration: Supports diagrams and visualisations using Mermaid’s Markdown-inspired text definitions:

Enhanced Printing: Improves browser printing by optionally redefining Markdown horizontal rules, e.g. *** as page breaks, and controlling print margins, page numbering, and title display where supported.

Theme Support: Provides multiple rendering themes, including Default, Black & White, and GitHub.