docs(parser): change parser documentation (#5262)

* changed parser documentation

* changed parser documentation

* changed parser documentation

* changed parser documentation

* change the code from the doc to examples folder

* add line highlights and fix sub header typo

* fix typos, pydantic install, and add built in envelope example

* changed the example from built in env to models

* fix validationerror import

* Changing highlights + import

* Changing highlights + import

* Changing highlights + import

* Addressing Andrea's feedback

---------

Signed-off-by: Ana Falcão <anafalcao@poli.ufrj.br>
Co-authored-by: Falcao <afalcao@bcd0744af793.ant.amazon.com>
Co-authored-by: Leandro Damascena <lcdama@amazon.pt>

Author: 3 people

.github/workflows/quality_check.yml

@@ -20,6 +20,7 @@ on:
     paths:
       - "aws_lambda_powertools/**"
       - "tests/**"
+      - "examples/**"
       - "pyproject.toml"
       - "poetry.lock"
       - "mypy.ini"
@@ -30,6 +31,7 @@ on:
     paths:
       - "aws_lambda_powertools/**"
       - "tests/**"
+      - "examples/**"
       - "pyproject.toml"
       - "poetry.lock"
       - "mypy.ini"