Failed to parse manifest - Virtual manifests must be configured with [workspace]

So I'm running this in powershell for my Rust project:

cargo build --target thumbv7em-none-eabihf

And it produces this error after I try to execute this command:

error: failed to parse manifest at C:\Users\PC\Downloads\Blizzard\Cargo.toml Caused by: virtual manifests must be configured with [workspace]

Here is my Cargo.toml file:

[package]
name = "my-project"
version = "0.1.0"
authors = ["runner"]
edition = "2021"

[profile.dev]
panic = "abort"

[profile.release]
panic = "abort"

If it's needed, here is my rust file:

#![no_std]
#![no_main]

use core::panic::PanicInfo;

#[no_mangle]
pub extern "C" fn _start() -> ! {
    loop {}
}

#[panic_handler]
fn panic(_info: &PanicInfo) -> ! {
    loop {}
}

And my file path looks like this:

> Blizzard
  > src
   > main.rs
  > Cargo.toml

How can I fix this issue? Any help is appreciated