update: aws-config README (#2221)

[Usage examples]: https://github.com/awslabs/aws-sdk-rust/tree/main/examples

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This crate is part of the [AWS SDK for Rust](https://awslabs.github.io/aws-sdk-rust/) and the [smithy-rs](https://github.com/awslabs/smithy-rs) code generator. In most cases, it should not be used directly.

This crate is part of the [AWS SDK for Rust](https://awslabs.github.io/aws-sdk-rust/) and the [smithy-rs](https://github.com/awslabs/smithy-rs) code generator.

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use std::fs;

use std::path::{Path, PathBuf};

const CRATES_TO_BE_USED_DIRECTLY: &[&str] = ["aws-config"].as_slice();

pub(crate) struct ReadmesExist;

impl Lint for ReadmesExist {

    fn name(&self) -> &str {

impl Fix for ReadmesHaveFooters {

    fn fix(&self, path: impl AsRef<Path>) -> Result<(Vec<LintError>, String)> {

        let (updated, new_contents) = fix_readme(path)?;

        let is_crate_to_be_used_directly = path

            .as_ref()

            .parent()

            .map(|parent_folder| {

                CRATES_TO_BE_USED_DIRECTLY

                    .iter()

                    .any(|crate_name| parent_folder.ends_with(crate_name))

            })

            .unwrap_or_default();

        let (updated, new_contents) = fix_readme(path, is_crate_to_be_used_directly)?;

        let errs = match updated {

            true => vec![LintError::new("README was missing required footer")],

            false => vec![],

    }

}

const README_FOOTER: &str = "\nThis crate is part of the [AWS SDK for Rust](https://awslabs.github.io/aws-sdk-rust/) \

and the [smithy-rs](https://github.com/awslabs/smithy-rs) code generator. In most cases, it should not be used directly.\n";

const README_FOOTER: &str =

    "\nThis crate is part of the [AWS SDK for Rust](https://awslabs.github.io/aws-sdk-rust/) \

and the [smithy-rs](https://github.com/awslabs/smithy-rs) code generator.";

const NOT_TO_BE_USED_DIRECTLY: &str = " In most cases, it should not be used directly.";

fn fix_readme(path: impl AsRef<Path>, to_be_used_directly: bool) -> Result<(bool, String)> {

    let mut footer_contents = README_FOOTER.to_string();

    if !to_be_used_directly {

        footer_contents.push_str(NOT_TO_BE_USED_DIRECTLY);

    }

    footer_contents.push('\n');

fn fix_readme(path: impl AsRef<Path>) -> Result<(bool, String)> {

    let mut contents = fs::read_to_string(path.as_ref())

        .with_context(|| format!("failure to read readme: {:?}", path.as_ref()))?;

    let updated = anchor::replace_anchor(&mut contents, &anchor::anchors("footer"), README_FOOTER)?;

    let updated =

        anchor::replace_anchor(&mut contents, &anchor::anchors("footer"), &footer_contents)?;

    Ok((updated, contents))

}