docs: add unmaintained notice (#41)

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mdbook-template"
-version = "1.1.0"
+version = "1.1.1+deprecated"
 edition = "2021"
 authors = ["Goudham Suresh <sgoudham@gmail.com>"]
 description = "A mdbook preprocessor that allows the re-usability of template files with dynamic arguments"

README.md

@@ -7,6 +7,11 @@
 
 > A mdbook preprocessor that allows the re-usability of template files with dynamic arguments
 
+> [!IMPORTANT]
+> **This package is no longer actively maintained**. I initially created this
+> when I was actively using mdBook for my website but am no longer doing so and
+> find it hard to motivate myself to work on this project.
+
 ## Table of Contents
 
 * [Author Notes](#author-notes)
@@ -297,4 +302,4 @@ before contributing!
 This preprocessor is heavily based off the
 [`links.rs`](https://github.com/rust-lang/mdBook/blob/master/src/preprocess/links.rs) file within
 [mdbook](https://github.com/rust-lang/mdBook) itself. I definitely wouldn't have been able to mock up something like
-this without the strong foundations that mdbook already implemented.
+this without the strong foundations that mdbook already implemented.