Use simple-mermaid from crates-io (#3304)

Re https://github.com/paritytech/polkadot-sdk/issues/2922

Changes:
- Use crates-io version of simple-mermaid as
[v0.1.1](https://github.com/glueball/simple-mermaid/releases/tag/v0.1.1)
supports no-std.
- Remove from `frame` since i did not see it used.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

Cargo.lock

@@ -5438,7 +5438,6 @@ dependencies = [
  "pallet-examples",
  "parity-scale-codec",
  "scale-info",
- "simple-mermaid",
  "sp-api",
  "sp-arithmetic",
  "sp-block-builder",
@@ -17488,8 +17487,9 @@ dependencies = [
 
 [[package]]
 name = "simple-mermaid"
-version = "0.1.0"
-source = "git+https://github.com/kianenigma/simple-mermaid.git?rev=e48b187bcfd5cc75111acd9d241f1bd36604344b#e48b187bcfd5cc75111acd9d241f1bd36604344b"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "620a1d43d70e142b1d46a929af51d44f383db9c7a2ec122de2cd992ccfcf3c18"
 
 [[package]]
 name = "siphasher"