Add missing ignore to snippets in the user guide

docs/user-guide/src/verify/resources_obligations.md

@@ -1,4 +1,4 @@
-# Resources and Obligations
+# Resources and obligations
 
 One way of describing state that is otherwise not captured by a Prusti program is using resources and obligations. They are typically produced and consumed by [`#[trusted]`](trusted.md) functions that have some external effects (e.g. by calling functions in foreign non-Rust libraries or by interacting with the real world).
 
@@ -27,7 +27,6 @@ resource! {
 The general syntax is
 
 ```rust,noplaypen,ignore
-
 resource! {
     fn resource_name(amount: usize, ...);
 }

docs/user-guide/src/verify/time_reasoning.md

@@ -22,22 +22,22 @@ The number of time steps a function needs to execute might also depend on the in
 
 The following are three more equivalent ways of specifying the same precondition of `do_work` as above.
 
-```rust,noplaygen
+```rust,noplaygen,ignore
 #[requires(time_credits(6))]
 #[requires(if more_work { time_credits(5) } else { true })]
 fn do_work(more_work: bool) {
     // ...
 }
 ```
 
-```rust,noplaypen
+```rust,noplaypen,ignore
 #[requires(time_credits(6) & (more_work ==> time_credits(5)))]
 fn do_work(more_work: bool) {
     // ...
 }
 ```
 
-```rust,noplaypen
+```rust,noplaypen,ignore
 #[requires(more_work ==> time_credits(11))]
 #[requires(!more_work ==> time_credits(6))]
 fn do_work(more_work: bool) {