add some readmes.

basic/README

@@ -0,0 +1,24 @@
+basic relayer
+=============
+
+  - a basic relay implementation based on relayer.
+  - uses postgres, which I think must be over version 12 since it uses generated columns.
+  - it has some antispam limits, tries to delete old stuff so things don't get out of control, and some other small optimizations, but it's something we can call "hardened".
+
+running
+-------
+
+grab a binary from the releases page and run it with the environment variable POSTGRESQL_DATABASE set to some postgres url:
+
+    POSTGRESQL_DATABASE=postgres://name:pass@localhost:5432/dbname ./relayer
+
+it also accepts a HOST and a PORT environment variables.
+
+compiling
+---------
+
+if you know Go you already know this:
+
+    go get github.com/fiatjaf/relayer/basic
+
+or something like that.