primitives: Add docs section for script hex API

In an effort to bring developer attention to the myriad of APIs for
parsing and formatting scripts as hex add a section to the rustodcs of
`Script` and `ScriptBuf` (same text for both).

primitives/src/script/borrowed.rs

@@ -49,6 +49,14 @@ internals::transparent_newtype! {
     /// The type is `#[repr(transparent)]` for internal purposes only!
     /// No consumer crate may rely on the representation of the struct!
     ///
+    /// # Hexadecimal strings
+    ///
+    /// Scripts are consensus encoded with a length prefix and as a result of this in some places in
+    /// the eccosystem one will encounter hex strings that include the prefix while in other places
+    /// the prefix is excluded. To support parsing and formatting scripts as hex we provide a bunch
+    /// of different APIs and trait implementations. Please see [`examples/script.rs`] for a
+    /// thorough example of all the APIs.
+    ///
     /// # Bitcoin Core References
     ///
     /// * [CScript definition](https://github.com/bitcoin/bitcoin/blob/d492dc1cdaabdc52b0766bf4cba4bd73178325d0/src/script/script.h#L410)

primitives/src/script/owned.rs

@@ -16,6 +16,15 @@ use crate::prelude::{Box, Vec};
 /// Just as other similar types, this implements [`Deref`], so [deref coercions] apply. Also note
 /// that all the safety/validity restrictions that apply to [`Script`] apply to `ScriptBuf` as well.
 ///
+/// # Hexadecimal strings
+///
+/// Scripts are consensus encoded with a length prefix and as a result of this in some places in the
+/// eccosystem one will encounter hex strings that include the prefix while in other places the
+/// prefix is excluded. To support parsing and formatting scripts as hex we provide a bunch of
+/// different APIs and trait implementations. Please see [`examples/script.rs`] for a thorough
+/// example of all the APIs.
+///
+/// [`examples/script.rs`]: <https://github.com/rust-bitcoin/rust-bitcoin/blob/master/bitcoin/examples/script.rs>
 /// [deref coercions]: https://doc.rust-lang.org/std/ops/trait.Deref.html#more-on-deref-coercion
 #[derive(Default, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
 pub struct ScriptBuf(Vec<u8>);