Attempt adding a search form for the mailing list

Copied from this search box: https://lists.autistici.org/splash/index.en.html

Author: ilario

communication.txt

@@ -11,6 +11,22 @@ The project communicate on the following mailing list
 * https://www.autistici.org/mailman/listinfo/libremesh[libremesh at krutt.org] -
   This list is used for project organisational purposes, user support, and development discussions. Any language is welcome.
 
+You can see the https://lists.autistici.org/list/libremesh.html[mailing list archive here] and search in it using this form:
+
+<form action="https://lists.autistici.org/cgi-lurker/keyword.cgi" accept-charset="UTF-8" onsubmit="form_timezone(this)">
+<input type="hidden" name="doc-url" value="https://lists.autistici.org">
+<input type="hidden" name="format" value="en.html">
+<input type="hidden" name="list" value="libremesh">
+<table><tbody>
+<tr><td colspan="2"><input type="text" name="query" class="longtext"><input type="submit" name="submit" value="Search!"></td></tr>
+<tr><td><b>Subject</b></td><td><input type="text" name="subject" class="longtext"></td></tr>
+<tr><td><b>Author</b></td><td><input type="text" name="author" class="longtext"></td></tr>
+<tr><td><b>Date</b></td><td><input type="hidden" name="utc" value="0"><input type="hidden" name="sec" value="00"><input type="hidden" name="min" value="00">
+<input type="hidden" name="hour" value="0">
+<select name="mday"><option value="1" selected="">1</option><option value="2">2</option><option value="3">3</option><option value="4">4</option><option value="5">5</option><option value="6">6</option><option value="7">7</option><option value="8">8</option><option value="9">9</option><option value="10">10</option><option value="11">11</option><option value="12">12</option><option value="13">13</option><option value="14">14</option><option value="15">15</option><option value="16">16</option><option value="17">17</option><option value="18">18</option><option value="19">19</option><option value="20">20</option><option value="21">21</option><option value="22">22</option><option value="23">23</option><option value="24">24</option><option value="25">25</option><option value="26">26</option><option value="27">27</option><option value="28">28</option><option value="29">29</option><option value="30">30</option><option value="31">31</option></select><select name="mon"><option value="1">January</option><option value="2">February</option><option value="3">March</option><option value="4">April</option><option value="5">May</option><option value="6">June</option><option value="7">July</option><option value="8">August</option><option value="9">September</option><option value="10">October</option><option value="11">November</option><option value="12" selected="">December</option></select><select name="year"><option value="2022">2022</option><option value="2023">2023</option><option value="2024">2024</option><option value="2025" selected="">2025</option></select></td></tr>
+</tbody></table></form>
+
+
 == Chatroom
 
 The chatroom can be accessed through Element app, desktop software or web client (link:https://element.io/personal[click here for checking out these chat clients]) and entering the `#libremesh-dev:matrix.guifi.net` chatroom. To write in the chatroom you'll need to register a user on any of the Matrix nodes (the default on element.io will also work). Other options for connecting can be found link:https://matrix.to/#/#libremesh-dev:matrix.guifi.net[clicking here].