mlua_derive: Update docs

Author: khvzak

docs/UserData.md

@@ -8,7 +8,7 @@ Named fields are exposed as readable and writable fields in Lua by default.
 Use `#[lua(...)]` on individual fields or methods to control how they are
 registered.
 
-```rust
+```rust,ignore
 use mlua::{Lua, Result, UserData};
 
 #[derive(UserData)]
@@ -92,7 +92,7 @@ At most one of `getter`, `setter`, `field` may be specified on a method.
 Constants in an `#[mlua::userdata_impl]` block are registered as static
 fields:
 
-```rust
+```rust,ignore
 #[mlua::userdata_impl]
 impl MyType {
     const VERSION: &str = "1.0";
@@ -108,7 +108,7 @@ Annotate a method with `#[lua(meta)]` to register it as a Lua metamethod.
 The metamethod name is inferred from the function name when it starts with
 `__`. Use `name = "..."` to specify the name explicitly.
 
-```rust
+```rust,ignore
 #[mlua::userdata_impl]
 impl MyType {
     #[lua(meta, infallible)]

docs/chunk.md

@@ -7,7 +7,7 @@ User's Rust types needs to implement [`UserData`] or [`IntoLua`] traits.
 
 Captured variables are **moved** into the chunk.
 
-```
+```rust
 use mlua::{Lua, Result, chunk};
 
 fn main() -> Result<()> {

docs/lua_module.md

@@ -2,7 +2,7 @@ Registers Lua module entrypoint.
 
 You can register multiple entrypoints as required.
 
-```ignore
+```rust,ignore
 use mlua::{Lua, Result, Table};
 
 #[mlua::lua_module]
@@ -19,7 +19,7 @@ You can also pass options to the attribute:
 
 * name - name of the module, defaults to the name of the function
 
-```ignore
+```rust,ignore
 #[mlua::lua_module(name = "alt_module")]
 fn my_module(lua: &Lua) -> Result<Table> {
     ...
@@ -33,7 +33,7 @@ limits or not. As a result, some operations that require memory allocation run i
 mode. Setting this attribute will improve performance of such operations with risk of having
 uncaught exceptions and memory leaks.
 
-```ignore
+```rust,ignore
 #[mlua::lua_module(skip_memory_check)]
 fn my_module(lua: &Lua) -> Result<Table> {
     ...