Readme changes.

README.md

@@ -3,6 +3,9 @@
 Quick and dirty crate for parsing values out of an environment var provided at
 compile time. See also: [docs](https://docs.rs/envparse).
 
+Feel free to [email me](chiovolonit@gmail.com) if I fail to notice a PR or issue in this
+repository (my github notifications are a mess).
+
 ## Usage
 Here's an example
 ```rs
@@ -23,7 +26,10 @@ struct Thing {
 }
 ```
 
-You can also `try`
+You can also `try` to parse the value, which always returns an Option. Note that if the user
+provided the value, but it was out of range, this will still fail with a compile error (rather
+than returning `None`), in order to let them know that their configuration was not/cannot be
+respected.
 
 ```rs
 const MAX_LEN_LOG2: u32 = match envparse::parse_env!(try "OPTIONAL_MAX_LEN_LOG2" as u32 in 0..32) {
@@ -35,6 +41,3 @@ struct Thing {
     len: [u8; MAX_LEN],
 }
 ```
-
-```
-