Doc fix

doc/reference/std/cli/shell.md

@@ -3,7 +3,9 @@
 The `:std/cli/shell` library provides facilities for working with Unix shell code
 
 ::: tip usage
+```scheme
 (import :std/cli/shell)
+```
 :::
 
 An earlier version of this library used to be available as `:clan/shell`
@@ -25,7 +27,7 @@ All other ASCII characters may require the string to be quoted.
 For good measure we also quote strings containing non-ASCII characters.
 
 ::: tip Examples:
-``` scheme
+```scheme
 > (string-for-each (lambda (c) (or (easy-shell-character? c) (error "foo")))
     "abcdefghijklmnopqrstuvwxzABCDEFGHIJKLMNOPQRSTUVWXZ012345678@%-_=+:,./") ;; no error
 > (string-for-each (lambda (c) (or (not (easy-shell-character? c)) (error "foo")))
@@ -43,7 +45,7 @@ The current implementation only trusts strings where every character
 satisfies `easy-shell-character?` to not require quoting.
 
 ::: tip Examples:
-``` scheme
+```scheme
 > (map needs-shell-escape ["foo?" "~user" "$1" "*.*" "!1" "ab\\cd" "{}" "a;b" "&" "|" "a b  c"])
 (#t #t #t #t #t #t #t #t #t #t #t)
 > (map needs-shell-escape ["foo" "%-_=+:,./" "1" "..." "abcd" "x=y:z,t.z/u+v_w"])
@@ -59,7 +61,7 @@ Given a `string`, returns a shell-escaped-string that,
 when included in a Unix shell command, will expand into the input `string`.
 
 ::: tip Examples:
-``` scheme
+```scheme
 > (map escape-shell-token ["foo?" "~user" "$1" "*.*" "!1" "ab\\cd" "{}" "a;b" "&" "|" "a b  c"])
 ("\"foo?\"" "\"~user\"" "\"\\$1\"" "\"*.*\"" "\"!1\"" "\"ab\\\\cd\"" "\"{}\"" "\"a;b\"" "\"&\"" "\"|\"" "\"a b  c\"")
 > (let (l ["foo" "%-_=+:,./" "1" "..." "abcd" "x=y:z,t.z/u+v_w"])
@@ -68,7 +70,7 @@ when included in a Unix shell command, will expand into the input `string`.
 ```
 :::
 
-### ->envvar
+### ->envvar
 ```scheme
 (->envvar . str) => environment-variable-name
 ```