Improve documentation for configuration

Although the configuration file was mostly wrapped to a line-width of
80, some lines were wrapped slightly shorter. I fixed this.

In general, all sentences were changed to start with a capital letter
and end with a period or other punctuation mark.

Many of the documentation commets read as, "config option to do XYZ". I
shortened these to simply "do XYZ".

clippy.toml

@@ -15,5 +15,5 @@ disallowed-macros = [
 ]
 
 disallowed-methods = [
-    { path = "tokio::spawn", reason = "use and pass conduuwit_core::server::Server::runtime() to spawn from"},
+    { path = "tokio::spawn", reason = "use and pass conduuwit_core::server::Server::runtime() to spawn from" },
 ]