Move usages folder to usage (#19757)

# Objective

There were 2 folders inside of `examples`, each with 1 example, and with
similar folder names.

## Solution

Move the example in the `usages` folder to `usage`.

## Testing
 
`cargo run -p ci`

Cargo.toml

@@ -607,7 +607,7 @@ web-sys = { version = "0.3", features = ["Window"] }
 
 [[example]]
 name = "context_menu"
-path = "examples/usages/context_menu.rs"
+path = "examples/usage/context_menu.rs"
 doc-scrape-examples = true
 
 [package.metadata.example.context_menu]

examples/README.md

@@ -584,7 +584,7 @@ Example | Description
 
 Example | Description
 --- | ---
-[Context Menu](../examples/usages/context_menu.rs) | Example of a context menu
+[Context Menu](../examples/usage/context_menu.rs) | Example of a context menu
 [Cooldown](../examples/usage/cooldown.rs) | Example for cooldown on button clicks
 
 ## Window