Add docstring to rustdoc conversion

Right now, only basic things are changed (remove ``@`` annotations, trim spaces, etc.).
In the future, changes will be made (mostly to _truly_ transform ``@param``to rustdoc conventions.

Right now, the documentation is mostly decent, and definitely understandable

ctru-sys/bindgen.sh

@@ -28,3 +28,5 @@ bindgen "$DEVKITPRO/libctru/include/3ds.h" \
     -DARM11 \
     -D__3DS__ \
 > src/bindings.rs
+
+cargo run --bin docstring-to-rustdoc -- src/bindings.rs

ctru-sys/src/bin/docstring-to-rustdoc.rs

@@ -0,0 +1,50 @@
+use std::{env, fs, io};
+use std::path::Path;
+
+fn main() -> io::Result<()> {
+    let args: Vec<String> = env::args().collect();
+
+    let bindings_path = Path::new(args.get(1).expect("bindings.rs not provided in the args"));
+    let bindings_string: String = fs::read_to_string(bindings_path)?;
+
+    let parsed = bindings_string
+        .lines()
+        .map(|v| {
+            // Only modify lines with the following structure: `` #[doc ... ] ``
+            if v.trim_start().starts_with("#[doc") && v.trim_end().ends_with("]") {
+                v
+                    .replace("@brief", "")
+                    // Example: ``@param offset Offset of the RomFS...`` -> ``- offset Offset of the RomFS...``
+                    // Will improve in the future
+                    .replace("@param", "* ")
+                    .replace("@ref", "")
+                    .replace("@note", "")
+                    .replace("@return", "")
+                    .replace("@sa", "")
+                    .replace("< ", "")
+                    // Remove things like ``@param[out]``
+                    .replace("[out]", "")
+                    .replace("[in]", "")
+                    // Trim start of the Rustdoc: ``...= " ...`` -> ``...= "...``
+                    .replace("= \" ", "= \"")
+                    // Double pass because _most_ annotations are at the start
+                    .replace("= \" ", "= \"")
+            } else {
+                String::from(v)
+            }
+        })
+        .map(|v| {
+            // End-lines of bindings.rs are CRLF
+            v + "\r\n"
+        })
+        .collect::<String>();
+
+    let old_bindings_path = bindings_path.to_str().unwrap().to_owned() + ".old";
+
+    // If something fails, the original bindings are available at ``bindings.rs.old``
+    fs::rename(bindings_path, &old_bindings_path)?;
+    fs::write(bindings_path, parsed)?;
+    fs::remove_file(&old_bindings_path)?;
+
+    Ok(())
+}