fix wording in README and literal expressions doc (#8970)

Author: viktorking7

README.md

@@ -49,7 +49,7 @@
 ### Prerequisites
 
 - Install [Rust](https://www.rust-lang.org/tools/install)
-- Setup Rust:
+- Set up Rust:
 ```bash
 rustup override set stable && rustup update
 ```

docs/reference/src/components/cairo/modules/language_constructs/pages/literal-expressions.adoc

@@ -62,7 +62,7 @@ Cairo syntax considers `-1` as an application of the xref:negation-operators.ado
 
 == Short string literals
 
-A short string is an ascii-string whose length is limited by the type that holds it.
+A short string is an ASCII string whose length is limited by the type that holds it.
 The default type is a `felt252` which limits the length of the string to 31 characters.
 A short string literal may be followed by an underscore character (`_`)
 and then a __literal suffix__ just like a numerical literal.