doc: mark Node.js v15.x as EOL

Today is 2021-06-01, which is the date v15.x release line is marked as End-of-Life. Refs: https://github.com/nodejs/Release/blob/main/schedule.json PR-URL: #38891 Reviewed-By: Richard Lau <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Tobias Nießen <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Nitzan Uziely <[email protected]>

Author: aduh95

CHANGELOG.md

@@ -3,7 +3,7 @@
 Select a Node.js version below to view the changelog history:
 
 *[Node.js 16](doc/changelogs/CHANGELOG_V16.md)**Current**
-*[Node.js 15](doc/changelogs/CHANGELOG_V15.md)**Current**
+*[Node.js 15](doc/changelogs/CHANGELOG_V15.md)End-of-Life
 *[Node.js 14](doc/changelogs/CHANGELOG_V14.md)**Long Term Support**
 *[Node.js 13](doc/changelogs/CHANGELOG_V13.md) End-of-Life
 *[Node.js 12](doc/changelogs/CHANGELOG_V12.md) Long Term Support
@@ -27,7 +27,6 @@ release.
 <table>
 <tr>
  <thtitle="Current"><ahref="doc/changelogs/CHANGELOG_V16.md">16</a><sup>Current</sup></th>
- <thtitle="Current"><ahref="doc/changelogs/CHANGELOG_V15.md">15</a><sup>Current</sup></th>
  <thtitle="LTS Until 2023-04"><ahref="doc/changelogs/CHANGELOG_V14.md">14</a><sup>LTS</sup></th>
  <thtitle="LTS Until 2022-04"><ahref="doc/changelogs/CHANGELOG_V12.md">12</a><sup>LTS</sup></th>
 </tr>
@@ -38,26 +37,6 @@ release.
 <ahref="doc/changelogs/CHANGELOG_V16.md#16.0.0">16.0.0</a><br/>
  </td>
  <tdvalign="top">
-<b><ahref="doc/changelogs/CHANGELOG_V15.md#15.14.0">15.14.0</a></b><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.13.0">15.13.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.12.0">15.12.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.11.0">15.11.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.10.0">15.10.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.9.0">15.9.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.8.0">15.8.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.7.0">15.7.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.6.0">15.6.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.5.1">15.5.1</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.5.0">15.5.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.4.0">15.4.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.3.0">15.3.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.2.1">15.2.1</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.2.0">15.2.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.1.0">15.1.0</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.0.1">15.0.1</a><br/>
-<ahref="doc/changelogs/CHANGELOG_V15.md#15.0.0">15.0.0</a><br/>
- </td>
- <tdvalign="top">
 <b><ahref="doc/changelogs/CHANGELOG_V14.md#14.16.1">14.16.1</a></b><br/>
 <ahref="doc/changelogs/CHANGELOG_V14.md#14.16.0">14.16.0</a><br/>
 <ahref="doc/changelogs/CHANGELOG_V14.md#14.15.5">14.15.5</a><br/>