remove std/ prefix from doc/lib.rst now that canonical import is shown in module docs (#17543)

* remove std/ prefix from doc/lib.rst now that canonical import is shown in module docs

* cleanup top docs for std/sha1

lib/std/sha1.nim

@@ -6,33 +6,26 @@
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
 #
-## **Note:** Import `std/sha1` to use this module.
-##
 ## [SHA-1 (Secure Hash Algorithm 1)](https://en.wikipedia.org/wiki/SHA-1)
 ## is a cryptographic hash function which takes an input and produces
 ## a 160-bit (20-byte) hash value known as a message digest.
 ##
-## Basic usage
-## ===========
-##
-runnableExamples:
-  let accessName = secureHash("John Doe")
-  assert $accessName == "AE6E4D1209F17B460503904FAD297B31E9CF6362"
-
-## .. code-block::
-##   let
-##     a = secureHashFile("myFile.nim")
-##     b = parseSecureHash("10DFAEBF6BFDBC7939957068E2EFACEC4972933C")
-##
-##   if a == b:
-##     echo "Files match"
-##
 ## See also
 ## ========
 ## * `base64 module<base64.html>`_ implements a Base64 encoder and decoder
 ## * `hashes module<hashes.html>`_ for efficient computations of hash values for diverse Nim types
 ## * `md5 module<md5.html>`_ implements the MD5 checksum algorithm
 
+runnableExamples:
+  let accessName = secureHash("John Doe")
+  assert $accessName == "AE6E4D1209F17B460503904FAD297B31E9CF6362"
+
+runnableExamples("-r:off"):
+  let
+    a = secureHashFile("myFile.nim")
+    b = parseSecureHash("10DFAEBF6BFDBC7939957068E2EFACEC4972933C")
+  assert a == b, "files don't match"
+
 import std/strutils
 from std/endians import bigEndian32, bigEndian64