Add missing links for Array#fetch_values (#63)

Co-authored-by: Herwin <herwinw@users.noreply.github.com>

Author: herwinw

3.4.md

@@ -566,7 +566,7 @@ A method that behaves like a mix between <a class="ruby-doc" href="https://docs.
   ary.fetch_values(1, 9, 5) { "default for #{it}" }
   #=> ["b", "default for 5", "default for 9"]
   ```
-* **Notes:** Unlike [Array#values_at](), the method only allows integer indexes (not ranges). The discussion of whether it should be adjusted is [ongoing]():
+* **Notes:** Unlike <a class="ruby-doc" href="https://docs.ruby-lang.org/en/3.4/Array.html#method-i-values_at"><code>Array#values_at</code></a>, the method only allows integer indexes (not ranges). The discussion of whether it should be adjusted is [ongoing](https://bugs.ruby-lang.org/issues/20953):
   ```ruby
   ary = %w[a b c d]
   ary.values_at(1, 2..5)

_src/3.4.md

@@ -566,7 +566,7 @@ A method that behaves like a mix between [Array#values_at](https://docs.ruby-lan
   ary.fetch_values(1, 9, 5) { "default for #{it}" }
   #=> ["b", "default for 5", "default for 9"]
   ```
-* **Notes:** Unlike [Array#values_at](), the method only allows integer indexes (not ranges). The discussion of whether it should be adjusted is [ongoing]():
+* **Notes:** Unlike [Array#values_at](https://docs.ruby-lang.org/en/3.4/Array.html#method-i-values_at), the method only allows integer indexes (not ranges). The discussion of whether it should be adjusted is [ongoing](https://bugs.ruby-lang.org/issues/20953):
   ```ruby
   ary = %w[a b c d]
   ary.values_at(1, 2..5)