briar/README.md: strikethrough Briar desktop not supporting forums

Although this is a small subset, it's good enough beginning and maybe I will fill it more in the future

Resolves: #51

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "gayming/fixcontroller.py"]
 	path = gayming/fixcontroller.py
 	url = https://gist.github.com/de2df973323b7c6acf45f40dc66e8db3.git
+[submodule "briar/forums/PandaCoderPL"]
+	path = briar/forums/PandaCoderPL
+	url = https://codeberg.org/PandaCoderPL/Briar-Forums.git

briar/README.md

@@ -32,8 +32,8 @@ this scheme or updating these files.
 Port: [it will pick one and try to stick with it](https://matrix.to/#/%23briar_desktop%3Atchncs.de/%24FKJk80vFnp2Fqnyov8g2S1QGJuY8SrJBlPjjqGSaW5M?via=pikaviestin.fi&via=matrix.org&via=dendrite.matrix.org&via=tchncs.de), so `sudo netstat -plnt` is your friend, look for `java`. It should be on LAN and link-local interfaces.
 
 I install it from Flathub and at the time of writing it doesn't support
-groups (where only creator can add users), forums (groups where everyone can
-add new users) or blogs.
+groups (where only creator can add users)<s>, forums (groups where everyone can
+add new users)</s> or blogs.
 
 ## Further reading and quotes
 

briar/forums/PandaCoderPL

@@ -0,0 +1 @@
+Subproject commit 68468da0f41967e6d791d057d0f79ee9e3677d2c

briar/forums/README.md

@@ -0,0 +1,24 @@
+# Lists of Briar forums
+
+Briar Forums are groups where anyone can add anyone. They have no further
+moderation options than people cutting contact with abusive users.
+
+* `PandaCoderPL` introduced many to Briar forums and messages from them are
+  visible in many forums especially those they list. To avoid duplication,
+  I have included their repository as a submodule.
+* `started-by-me.csv` has those I created, but due to the way how Briar
+  works I have no special access/power over others there.
+  * This is intentionally missing forums that contain just me and another
+    person with multiple devices as Briar doesn't have multidevice support
+    and groups being untransferrable is too painful to use them, although
+    it carries risk of someone accidentally oversharing forums and thus
+    revealing past messages. A dead friend forum where everyone else may
+    have stopped using Briar is also omitted.
+  * I mostly have `date +%Y-%j` in the end of forums I create so in case
+    someone else has the same idea, there is unlikely to be two forums with
+    the exact same name (which is possible and not a problem for Briar).
+
+I am on many forums and open to forum shares although I have been rejecting
+languages I consider more excotic for me. I don't understand everything going
+on them or should look into some subjects more deeply in order to decide am
+I comfortable sharing some.

briar/forums/started-by-me.csv

@@ -0,0 +1,7 @@
+Name,Description,Comment
+Yggdrasil Network 2022-321,,
+Light pollution 2023-001,,
+Walking 2023-001,,
+Keyoxide 2023-031,,
+LaTeX 2023-031,,
+Briar Introducers 2023-039,,