Fix deployment on Windows (#453)

Co-authored-by: Antonio Vivace <[email protected]>

Author: alloncm

DEPLOY.md

@@ -2,15 +2,15 @@
 
 This document will explain you how to run a local copy of Pan Docs. 
 
-1. Install [Rust](https://www.rust-lang.org/tools/install), [mdBook](https://github.com/rust-lang/mdBook#readme), and [Python 3](https://www.python.org/downloads).
+1. Install [Rust](https://www.rust-lang.org/tools/install), [mdBook](https://github.com/rust-lang/mdBook#readme), and [Python 3](https://www.python.org/downloads) (3.9 or an earlier version).
   mdBook is the tool rendering the documentation, Rust is used for some custom plugins and Python scripts are used to render some images. E.g.:
   ```sh
   # Install Rust using rustup
   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
   # Install mdbook using cargo
   cargo install mdbook
   # Remember to add cargo bin directory to your path
-  # Install python3 (on Debian systems)
+  # Install Python; e.g. on Debian-based systems:
   apt install python3
   ```
 2. [Install the Python prerequisites](https://packaging.python.org/tutorials/installing-packages/#requirements-files).

renderer/src/main.rs

@@ -88,7 +88,7 @@ impl Renderer for Pandocs {
         // Generate the graphs in `imgs/src/` by shelling out to Python
         let working_dir = ctx.destination.join("imgs");
         let src_dir = working_dir.join("src");
-        let python = if cfg!(windows) { "py3" } else { "python3" };
+        let python = if cfg!(windows) { "python" } else { "python3" };
         let gen_graph = |file_name, title| {
             let mut file_name = PathBuf::from_str(file_name).unwrap(); // Can't fail
             let output = File::create(working_dir.join(&file_name))?;