Fix some link paths to reduce MkDocs warnings

Author: schoen

docs/getting-started/welcome-evm.md

@@ -13,7 +13,7 @@ We know security is your top concern. Simplicity is fundamentally architected wi
 ## Where to go from here:
 
 * **Perform a live transaction:** Try our [quickstart tutorial](../quickstart/) to make your first Simplicity transaction in minutes.
-* **Get introduced to Simplicity from the EVM perspective**: Map your knowledge to our environment by reading our dedicated, detailed [Introduction to Simplicity for EVM Developers](../../documentation/simplicity-for-evm-developers), including frequently asked questions and a video presentation on the architectural differences.
+* **Get introduced to Simplicity from the EVM perspective**: Map your knowledge to our environment by reading our dedicated, detailed [Introduction to Simplicity for EVM Developers](../documentation/simplicity-for-evm-developers), including frequently asked questions and a video presentation on the architectural differences.
 * **See it in action:** Explore what's possible with [Simplicity use cases and demos](../../use-cases/), including how complex financial applications are built natively on-chain.
 * **Shift your mental model:** Dive into the [UTXO execution model](../../documentation/execution-model) that structures Simplicity contracts and within which they execute on the blockchain. Understand how Simplicity enforces financial logic and spending conditions without global state or account balances.
 * **Master state management:** Learn how to pass data from one transaction to another using [covenants and state management](../../documentation/state), the UTXO equivalent to updating contract storage.

docs/simplicityhl-reference/builtin.md

@@ -1,6 +1,6 @@
 # Built-in functions
 
-[SimplicityHL](../glossary.md#simplicityhl) offers several built-in functions and macros. These are additional to the hundreds of [jets](../../documentation/jets) provided by the Simplicity Elements integration.
+[SimplicityHL](../glossary.md#simplicityhl) offers several built-in functions and macros. These are additional to the hundreds of [jets](../../documentation/jets/) provided by the Simplicity Elements integration.
 
 | <div style="width:8em">Function</div> | Description |
 |-------------|-----------------------------------|
@@ -9,7 +9,7 @@
 | `dbg!()` | Do-nothing function used as a debugger marker. |
 | `fold()` | Repeatedly apply a function to each element of a list, starting with an initial accumulator value. |
 | `for_while()` | Perform a bounded loop by repeatedly calling a function with an incrementing counter variable. Permits an explicit early exit from the loop.<br><br>**Note: can be computationally expensive.** |
-| `<T>::into()` | Perform native type conversions. See [type casting](../type_casting) for more details. |
+| `<T>::into()` | Perform native type conversions. See [type casting](../type_casting/) for more details. |
 | `is_none<T>()` | Check whether an `Option<T>` value is `None`, returning `true` or `false`. |
 | `panic!` | Immediately abort the current program, rejecting the currently proposed transaction. |
 | `unwrap` | Require that a value of type `Option<T>` is `Some`, extracting the underlying element of type `T`. Panics if the given value is `None` instead. |
@@ -105,7 +105,7 @@ fn not(bit: bool) -> bool {
 }
 ```
 
-See [type casting](../type_casting) for more details.
+See [type casting](../type_casting/) for more details.
 
 ### `is_none`