Modify release note URL in documentation page.

Author: Taiki Koshino

_pages/documentation.md

@@ -17,9 +17,9 @@ Please select your preferred version and language from the options below.
 | Version             | Documentation      |
 | ------------------- | -------------------|
 | **4.7 (latest)**        | <i class='fas fa-file-lines'></i> [English](/docs/4.7/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.7/ja/html/)   |
-| **4.6**        | <i class='fas fa-file-lines'></i> [English](/docs/4.6/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.6/en/html/)   |
-| **4.5**        | <i class='fas fa-file-lines'></i> [English](/docs/4.5/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.5/en/html/)   |
-| **4.4**        | <i class='fas fa-file-lines'></i> [English](/docs/4.4/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.4/en/html/)   |
+| **4.6**        | <i class='fas fa-file-lines'></i> [English](/docs/4.6/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.6/ja/html/)   |
+| **4.5**        | <i class='fas fa-file-lines'></i> [English](/docs/4.5/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.5/ja/html/)   |
+| **4.4**        | <i class='fas fa-file-lines'></i> [English](/docs/4.4/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.4/ja/html/)   |
 | **4.3**        | <i class='fas fa-file-lines'></i> [English](/docs/4.3/en/html/)  <i class='fas fa-file-lines'></i> [Japanese](/docs/4.3/ja/html/)   |
 
 ## Tutorials of Pgpool-II