feat(just_template): add proc-macro `tmpl!` and restructure crate

Move the old `tmpl!` and `tmpl_param!` macros into a dedicated
`just_template_macros` proc-macro crate. The new `tmpl!` macro supports
both simple parameter assignment and multi-arm implementation blocks
with per-arm overrides. Remove the deprecated `deprecated` module and
update tests accordingly.

1 files changed, 9 insertions, 0 deletions

diff --git a/just_template/src/template.rs b/just_template/src/template.rs
index e368917..953d7a5 100644
--- a/just_template/src/template.rs
+++ b/just_template/src/template.rs
@@ -1,9 +1,18 @@
 use std::collections::HashMap;
 
+/// Template struct, used to represent a template composed of a template string and parameters.
+///
+/// # Fields
+/// - `template_str` - Template string containing placeholders.
+/// - `params` - Normal parameters, key-value mappings.
+/// - `impl_params` - Implementation block parameters, where each implementation block name corresponds to a list of parameter maps (each parameter map is a key-value mapping).
 #[derive(Default, Clone)]
 pub struct Template {
+    /// Template string containing placeholders such as `{{param_name}}`.
     pub(crate) template_str: String,
+    /// Normal parameters, keyed by parameter name with values as parameter values.
     pub(crate) params: HashMap<String, String>,
+    /// Implementation block parameters, keyed by implementation block name with values as a list of parameter maps.
     pub(crate) impl_params: HashMap<String, Vec<HashMap<String, String>>>,
 }