feat: add "deno init" subcommand (#15469)

This adds an init subcommand to that creates a project starter similar to cargo init.

```
$ deno init my_project
Project initialized
Run these commands to get started:
  cd my_project
  deno run main.ts
  deno run main_test.ts
$ deno run main.ts
Add 2 + 3 5
$ cat main.ts
export function add(a: number, b: number): number {
  return a + b;
}
if (import.meta.main) {
  console.log("Add 2 + 3", add(2, 3));
}
$ cat main_test.ts
import { assertEquals } from "https://deno.land/std@0.151.0/testing/asserts.ts";
import { add } from "./main.ts";
Deno.test(function addTest() {
    assertEquals(add(2, 3), 5);
});
```

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/cli/main.rs b/cli/main.rs
index b157b3582..db625e404 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -51,6 +51,7 @@ use crate::args::EvalFlags;
 use crate::args::Flags;
 use crate::args::FmtFlags;
 use crate::args::InfoFlags;
+use crate::args::InitFlags;
 use crate::args::InstallFlags;
 use crate::args::LintFlags;
 use crate::args::ReplFlags;
@@ -273,6 +274,14 @@ async fn compile_command(
   Ok(0)
 }
 
+async fn init_command(
+  _flags: Flags,
+  init_flags: InitFlags,
+) -> Result<i32, AnyError> {
+  tools::init::init_project(init_flags).await?;
+  Ok(0)
+}
+
 async fn info_command(
   flags: Flags,
   info_flags: InfoFlags,
@@ -941,6 +950,9 @@ fn get_subcommand(
     DenoSubcommand::Fmt(fmt_flags) => {
       format_command(flags, fmt_flags).boxed_local()
     }
+    DenoSubcommand::Init(init_flags) => {
+      init_command(flags, init_flags).boxed_local()
+    }
     DenoSubcommand::Info(info_flags) => {
       info_command(flags, info_flags).boxed_local()
     }