fix(distributions) update the certified distribution matrix

Signed-off-by: Benoit Mortier <benoit.mortier@fusiondirectory.org>

source/fusiondirectory/distribution/certified-distribution.rst

@@ -4,22 +4,20 @@ Certified distributions
 
 We certify FusionDirectory with all the most common distributions, here is a table which summarizes the level of support by distribution and version.
 
-Fusiondirectory need at least PHP 5.6.
+ * Fusiondirectory 1.4 need = PHP 7.4 
 
- * Fusiondirectory 1.3 need >= PHP 5.6 
- * Fusiondirectory 1.4 need >= PHP 7.0
+================= ========================
+DISTRIBUTION      FusionDirectory 1.4
+================= ========================
+Debian Buster     supported
+Debian Bullseyes  supported
+----------------- ------------------------
+Ubuntu 16.04 LTS  not supported
+Ubuntu 18.04 LTS  supported ²
+Ubuntu 20.04 LTS  supported
+----------------- ------------------------
+Centos 7          supported
+Centos 8          not supported
+================= ========================
 
-================= ======================== =======================
-DISTRIBUTION      FusionDirectory 1.2      FusionDirectory 1.3
-================= ======================== =======================
-Debian Jessie     need a support contract  need a support contract
-Debian Stretch    not supported            supported
-Debian Buster     not supported            supported
------------------ ------------------------ -----------------------
-Ubuntu 16.04 LTS  need a support contract  supported
-Ubuntu 18.04 LTS  not supported            supported
-Ubuntu 20.04 LTS  not supported            work in progress
------------------ ------------------------ -----------------------
-Centos 7          need a support contract  supported
-Centos 8          not supported            not supported
-================= ======================== =======================
+² need to add the ppa of the php ubuntu maintener