feat: set message for multiple revsets

Allows to set the revision message of multiple revisions by passing
them as arguments. This only supports simple revisions, such as `@`,
`@-`, `xs`, and so on. Comple revisions such as `@..@-` are not
supported.

Fixes: #5

Cargo.lock

@@ -237,8 +237,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c673075a2e0e5f4a1dde27ce9dee1ea4558c7ffe648f576438a20ca1d2acc4b0"
 dependencies = [
  "iana-time-zone",
+ "js-sys",
  "num-traits",
  "serde",
+ "wasm-bindgen",
  "windows-link",
 ]
 
@@ -1655,6 +1657,7 @@ dependencies = [
  "assert_cmd",
  "assert_fs",
  "async-trait",
+ "chrono",
  "clap",
  "etcetera",
  "git-conventional",