Fix assertion message (#216)

- [x] I agree to follow the project's [code of
conduct](https://github.com/georust/geo/blob/master/CODE_OF_CONDUCT.md).
- [x] I added an entry to `rstar/CHANGELOG.md` if knowledge of this
change could be valuable to users.
---
The assertion requires MAX_SIZE >= 4 while the message requires MAX_SIZE
> 4, so the message should be changed into "MAX_SIZE too small. Must be
at least 4.".

Author: YichiZhang0613

rstar/CHANGELOG.md

@@ -10,6 +10,7 @@
 - Made `RStar` methods take `Point` and `Envelope` as owned values where it makes sense ([PR](https://github.com/georust/rstar/pull/189))
 - Fix Clippy warning (surfaced in Rust 1.89) related to lifetime elision
 - MSRV is now 1.68 (2023-03-09)
+- Fix incorrect assertion message in `verify_parameters` of `rstar/src/params.rs`
 
 
 # 0.12.2

rstar/src/params.rs

@@ -88,10 +88,7 @@ pub trait InsertionStrategy {
 }
 
 pub fn verify_parameters<T: RTreeObject, P: RTreeParams>() {
-    assert!(
-        P::MAX_SIZE >= 4,
-        "MAX_SIZE too small. Must be larger than 4."
-    );
+    assert!(P::MAX_SIZE >= 4, "MAX_SIZE too small. Must be at least 4.");
 
     assert!(P::MIN_SIZE > 0, "MIN_SIZE must be at least 1",);
     let max_min_size = (P::MAX_SIZE + 1) / 2;