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, 14 insertions, 0 deletions

diff --git a/just_template_macros/Cargo.toml b/just_template_macros/Cargo.toml
new file mode 100644
index 0000000..c033d1b
--- /dev/null
+++ b/just_template_macros/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "just_template_macros"
+version.workspace = true
+description.workspace = true
+authors.workspace = true
+edition.workspace = true
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0.106"
+quote = "1.0.46"
+syn = { version = "2.0.118", features = ["full", "extra-traits"] }