markdown formatting in messages, sharper tool descriptions

Cargo.lock

@@ -2623,6 +2623,24 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "pulldown-cmark"
+version = "0.13.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c3a14896dfa883796f1cb410461aef38810ea05f2b2c33c5aded3649095fdad"
+dependencies = [
+ "bitflags",
+ "memchr",
+ "pulldown-cmark-escape",
+ "unicase",
+]
+
+[[package]]
+name = "pulldown-cmark-escape"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "007d8adb5ddab6f8e3f491ac63566a7d5002cc7ed73901f72057943fa71ae1ae"
+
 [[package]]
 name = "quote"
 version = "1.0.45"
@@ -3011,6 +3029,7 @@ dependencies = [
  "js_int",
  "js_option",
  "percent-encoding",
+ "pulldown-cmark",
  "regex",
  "ruma-common",
  "ruma-identifiers-validation",
@@ -4130,6 +4149,12 @@ dependencies = [
  "web-time",
 ]
 
+[[package]]
+name = "unicase"
+version = "2.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbc4bc3a9f746d862c45cb89d705aa10f187bb96c76001afab07a0d35ce60142"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.24"