fix(clippy): Fix clippy lints in docs (#365)

* Fix commented out code in lib.rs docs not found in README.md

* Fix clippy lints in README.md and lib.rs

README.md

@@ -132,7 +132,6 @@ fn this_fails() -> Result<()> {
     // You can use plain strings as a `Source`, or anything that implements
     // the one-method `Source` trait.
     let src = "source\n  text\n    here".to_string();
-    let len = src.len();
 
     Err(MyBad {
         src: NamedSource::new("bad_file.rs", src),
@@ -247,7 +246,7 @@ use miette::{IntoDiagnostic, Result};
 use semver::Version;
 
 pub fn some_tool() -> Result<Version> {
-    Ok("1.2.x".parse().into_diagnostic()?)
+    "1.2.x".parse().into_diagnostic()
 }
 ```
 
@@ -262,24 +261,24 @@ use miette::{IntoDiagnostic, Result, WrapErr};
 use semver::Version;
 
 pub fn some_tool() -> Result<Version> {
-    Ok("1.2.x"
+    "1.2.x"
         .parse()
         .into_diagnostic()
-        .wrap_err("Parsing this tool's semver version failed.")?)
+        .wrap_err("Parsing this tool's semver version failed.")
 }
 ```
 
 To construct your own simple adhoc error use the [miette!] macro:
 ```rust
 // my_app/lib/my_internal_file.rs
-use miette::{miette, IntoDiagnostic, Result, WrapErr};
+use miette::{miette, Result};
 use semver::Version;
 
 pub fn some_tool() -> Result<Version> {
     let version = "1.2.x";
-    Ok(version
+    version
         .parse()
-        .map_err(|_| miette!("Invalid version {}", version))?)
+        .map_err(|_| miette!("Invalid version {}", version))
 }
 ```
 There are also similar [bail!] and [ensure!] macros.

src/lib.rs

@@ -131,7 +131,6 @@
 //!     // You can use plain strings as a `Source`, or anything that implements
 //!     // the one-method `Source` trait.
 //!     let src = "source\n  text\n    here".to_string();
-//!     let len = src.len();
 //!
 //!     Err(MyBad {
 //!         src: NamedSource::new("bad_file.rs", src),
@@ -246,7 +245,7 @@
 //! use semver::Version;
 //!
 //! pub fn some_tool() -> Result<Version> {
-//!     Ok("1.2.x".parse().into_diagnostic()?)
+//!     "1.2.x".parse().into_diagnostic()
 //! }
 //! ```
 //!
@@ -261,24 +260,24 @@
 //! use semver::Version;
 //!
 //! pub fn some_tool() -> Result<Version> {
-//!     Ok("1.2.x"
+//!     "1.2.x"
 //!         .parse()
 //!         .into_diagnostic()
-//!         .wrap_err("Parsing this tool's semver version failed.")?)
+//!         .wrap_err("Parsing this tool's semver version failed.")
 //! }
 //! ```
 //!
 //! To construct your own simple adhoc error use the [miette!] macro:
 //! ```rust
 //! // my_app/lib/my_internal_file.rs
-//! use miette::{miette, IntoDiagnostic, Result, WrapErr};
+//! use miette::{miette, Result};
 //! use semver::Version;
 //!
 //! pub fn some_tool() -> Result<Version> {
 //!     let version = "1.2.x";
-//!     Ok(version
+//!     version
 //!         .parse()
-//!         .map_err(|_| miette!("Invalid version {}", version))?)
+//!         .map_err(|_| miette!("Invalid version {}", version))
 //! }
 //! ```
 //! There are also similar [bail!] and [ensure!] macros.
@@ -637,7 +636,6 @@
 //!     )
 //! }))
 //!
-//! # .unwrap()
 //! ```
 //!
 //! See the docs for [`MietteHandlerOpts`] for more details on what you can