doc: simplify links for release notes

Change-Id: If9e3c5a58726ae3628d2e835d71f1a4708594c11
Reviewed-on: https://go-review.googlesource.com/c/go/+/586575
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Jonathan Amsterdam <[email protected]>

Author: callthingsoff

doc/next/6-stdlib/2-unique.md

@@ -1,6 +1,6 @@
 ### New unique package
 
-The new [unique](/pkg/unique) package provides facilities for
+The new [unique] package provides facilities for
 canonicalizing values (like "interning" or "hash-consing").
 
 Any value of comparable type may be canonicalized with the new

doc/next/6-stdlib/3-iter.md

@@ -1,10 +1,9 @@
 ### Iterators
 
-The new [`iter` package](/pkg/iter/) provides the basic definitions for
-working with user-defined iterators.
+The new [iter] package provides the basic definitions for working with
+user-defined iterators.
 
-The [`slices` package](/pkg/slices/) adds several functions that work
-with iterators:
+The [slices] package adds several functions that work with iterators:
 - [All](/pkg/slices#All) returns an iterator over slice indexes and values.
 - [Values](/pkg/slices#Values) returns an iterator over slice elements.
 - [Backward](/pkg/slices#Backward) returns an iterator that loops over
@@ -22,8 +21,7 @@ with iterators:
 - [Chunk](/pkg/slices#Chunk) returns an iterator over consecutive
   sub-slices of up to n elements of a slice.
 
-The [`maps` package](/pkg/maps/) adds several functions that work
-with iterators:
+The [maps] package adds several functions that work with iterators:
 - [All](/pkg/maps#All) returns an iterator over key-value pairs from m.
 - [Keys](/pkg/maps#Keys) returns an iterator over keys in m.
 - [Values](/pkg/maps#Values) returns an iterator over values in m.

doc/next/6-stdlib/99-minor/sync/atomic/61395.md

@@ -1,3 +1,3 @@
 <!-- Issue #61395 -->
-The new [`atomic.And`](/pkg/sync/atomic#And) and [`atomic.Or`](/pkg/sync/atomic#Or)
-operators apply a bitwise `AND` or `OR` to the given input, returning the old value.
+The new [And] and [Or] operators apply a bitwise `AND` or `OR` to
+the given input, returning the old value.