docs/

Enhancing all the .rst doc files by adding highlighting for the code snippets, including the following langs:
1. Solidity

2. bash

3. javascript

4. assembly

docs/types/mapping-types.rst

@@ -40,7 +40,7 @@ an Ethereum address to an unsigned integer value. As ``uint`` is a value type, t
 returns a value that matches the type, which you can see in the ``MappingUser``
 contract that returns the value at the specified address.
 
-::
+.. code-block:: solidity
 
     // SPDX-License-Identifier: GPL-3.0
     pragma solidity >=0.4.0 <0.9.0;
@@ -66,7 +66,7 @@ The example below is a simplified version of an
 ``_allowances`` is an example of a mapping type inside another mapping type.
 The example below uses ``_allowances`` to record the amount someone else is allowed to withdraw from your account.
 
-::
+.. code-block:: solidity
 
     // SPDX-License-Identifier: GPL-3.0
     pragma solidity >=0.4.22 <0.9.0;
@@ -121,7 +121,7 @@ top of them and iterate over that. For example, the code below implements an
 ``IterableMapping`` library that the ``User`` contract then adds data too, and
 the ``sum`` function iterates over to sum all the values.
 
-::
+.. code-block:: solidity
 
     // SPDX-License-Identifier: GPL-3.0
     pragma solidity >=0.6.8 <0.9.0;