Update README, CHANGELOG

CHANGELOG.md

@@ -1,3 +1,8 @@
+## v2.5.0 → v2.6.0
+  * Perf: make ns filtering a compile-time check.
+  * Perf: add support for a compile-time logging level environment variable (`TIMBRE_LOG_LEVEL`). See `timbre/compile-time-level` docstring for details.
+
+
 ## v2.4.1 → v2.5.0
   * Added `:file` and `:line` appender args.
   * Fixed `make-timestamp-fn` thread safety.

README.md

@@ -11,7 +11,8 @@ Logging with Java can be maddeningly, unnecessarily hard. Particularly if all yo
 ## What's in the box™?
  * Small, uncomplicated **all-Clojure** library.
  * **Super-simple map-based config**: no arcane XML or properties files!
- * **Decent performance** (low overhead).
+ * **Low overhead** with dynamic logging level.
+ * **No overhead** with compile-time logging level. (v2.6+)
  * Flexible **fn-centric appender model** with **middleware**.
  * Sensible built-in appenders including simple **email appender**.
  * Tunable **rate limit** and **asynchronous** logging support.
@@ -58,6 +59,16 @@ There's little overhead for checking logging levels:
 %> "Elapsed time: 0.051 msecs"
 ```
 
+And _no_ overhead when using a compile-time logging level (set `TIMBRE_LOG_LEVEL` environment variable):
+
+```clojure
+(time (dotimes [_ 1000000000] (trace (Thread/sleep 5000))))
+%> "Elapsed time: 387.159 msecs"
+
+(time (dotimes [_ 1000000000] nil))
+%> "Elapsed time: 389.231 msecs"
+```
+
 First-argument exceptions generate a stack trace:
 
 ```clojure