rename "examples" to "demos" to avoid confusion with Cargo examples

I got confused because I tried to run the player with:

cargo run --examples demo_player

However this did not work because demo_player is structured as a
subcrate in a workspace, not as an example. Cargo examples do not
have a src directory nor their own Cargo.toml:
https://doc.rust-lang.org/cargo/guide/project-layout.html

Unfortunately there is no way to specify dependencies only for an
example. There is an open RFC for that:
rust-lang/rfcs#2887

So for now, I think it is best to leave the demo applications as
subcrates in a workspace, but rename the "examples" directory to
"demos" so people don't think they will work with
cargo run --examples

Author: Be-ing

Cargo.toml

@@ -21,8 +21,8 @@ members = [
     "core",
     "decode_wav",
     "encode_wav",
-    "examples/demo_player",
-    "examples/demo_writer",
+    "demos/player",
+    "demos/writer",
 ]
 
 [features]

examples/demo_player/Cargo.toml renamed to demos/player/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "demo_player"
+name = "player"
 version = "0.1.0"
 authors = ["Billy Messenger <[email protected]>"]
 edition = "2018"
@@ -11,4 +11,4 @@ publish = false
 creek = { path = "../../" }
 eframe = "0.9.0"
 rtrb = "0.2"
-cpal = "0.13"
+cpal = "0.13"

examples/demo_player/README.md renamed to demos/player/README.md

@@ -1,5 +1,5 @@
 [package]
-name = "demo_writer"
+name = "writer"
 version = "0.1.0"
 authors = ["Billy Messenger <[email protected]>"]
 edition = "2018"
@@ -11,4 +11,4 @@ publish = false
 creek = { path = "../../" }
 eframe = "0.9.0"
 rtrb = "0.2"
-cpal = "0.13"
+cpal = "0.13"