example: rust: msgpack: Update prerequisites and filename

Signed-off-by: Hiroshi Hatake <[email protected]>

examples/filter_rust_msgpack/README.md

@@ -1,11 +1,11 @@
-# Fluent Bit / filter_rust
+# Fluent Bit / filter_rust_msgpack
 
-This source source tree provides an example of WASM program written in Rust.
+This source source tree provides an example of WASM program which uses msgpack format written in Rust.
 
 ## Prerequisites
 
 * Rust
-  * rustc 1.61.0 (fe5b13d68 2022-05-18) or later
+  * rustc 1.75.0 (82e1608df 2023-12-21)) or later
 * [rustup](https://rustup.rs/) (For preparing rust compiler and toolchains)
 
 ## How to build
@@ -49,8 +49,8 @@ Create fluent-bit configuration file as follows:
 [FILTER]
     Name   wasm
     match  dummy.*
-    WASM_Path /path/to/filter_rust_rmp.wasm
-    Function_Name rust_filter_rmp
+    WASM_Path /path/to/filter_rust_msgpack.wasm
+    Function_Name rust_filter_msgpack
     accessible_paths .,/path/to/fluent-bit
 
 [OUTPUT]