1.Updated Substrate installation link

Before:

$ curl https://getsubstrate.io/ -ssf | bash -s -- --fast
After:

$ curl https://docs.substrate.io/install/ -ssf | bash -s -- --fast**

Explanation: Replaced an outdated Substrate installation link with the correct one (docs.substrate.io/install/).

2. Fixed incorrect command (non_std → no_std)

Before:
Right now, if non_std is required, default-features = false must be set in the root Cargo.toml file (related to this issue). Otherwise, it will have no effect, causing your compilation to fail.

After:
Right now, if no_std is required, default-features = false must be set in the root Cargo.toml file (related to this issue). Otherwise, it will have no effect, causing your compilation to fail.

Explanation:
Fixed a typo in the flag name: "non_std" was incorrect and was replaced with "no_std", which is the correct Rust terminology for using a standard library-free environment.
Elimination of Potential Errors: The incorrect use of the term "non_std" could lead to misunderstandings about how to properly configure the project, which may cause compilation issues. Correcting this terminology helps prevent such errors.