Update README and Makefile

* Update letter case in section headers and
  'make help' documentation
* Tidy header comments in Makefile

Author: jonavellecuerdo

Makefile

@@ -1,51 +1,57 @@
 SHELL=/bin/bash
 DATETIME:=$(shell date -u +%Y%m%dT%H%M%SZ)
 
-help: # preview Makefile commands
+help: # Preview Makefile commands
 	@awk 'BEGIN { FS = ":.*#"; print "Usage:  make <target>\n\nTargets:" } \
 /^[-_[:alpha:]]+:.?*#/ { printf "  %-15s%s\n", $$1, $$2 }' $(MAKEFILE_LIST)
 
-## ---- Dependency commands ---- ##
+#######################
+# Dependency commands
+#######################
 
-install: # install Python dependencies
+install: # Install Python dependencies
 	pipenv install --dev
 	pipenv run pre-commit install
 
-update: install # update Python dependencies
+update: install # Update Python dependencies
 	pipenv clean
 	pipenv update --dev
 
-## ---- Unit test commands ---- ##
+######################
+# Unit test commands
+######################
 
-test: # run tests and print a coverage report
+test: # Run tests and print a coverage report
 	pipenv run coverage run --source=lambdas -m pytest -vv
 	pipenv run coverage report -m
 
-coveralls: test # write coverage data to an LCOV report
+coveralls: test # Write coverage data to an LCOV report
 	pipenv run coverage lcov -o ./coverage/lcov.info
 
-## ---- Code quality and safety commands ---- ##
+####################################
+# Code quality and safety commands
+####################################
 
-lint: black mypy ruff safety # run linters
+lint: black mypy ruff safety # Run linters
 
-black: # run 'black' linter and print a preview of suggested changes
+black: # Run 'black' linter and print a preview of suggested changes
 	pipenv run black --check --diff .
 
-mypy: # run 'mypy' linter
+mypy: # Run 'mypy' linter
 	pipenv run mypy .
 
-ruff: # run 'ruff' linter and print a preview of errors
+ruff: # Run 'ruff' linter and print a preview of errors
 	pipenv run ruff check .
 
-safety: # check for security vulnerabilities and verify Pipfile.lock is up-to-date
+safety: # Check for security vulnerabilities and verify Pipfile.lock is up-to-date
 	pipenv check
 	pipenv verify
 
-lint-apply: # apply changes with 'black' and resolve 'fixable errors' with 'ruff'
+lint-apply: # Apply changes with 'black' and resolve 'fixable errors' with 'ruff'
 	black-apply ruff-apply 
 
-black-apply: # apply changes with 'black'
+black-apply: # Apply changes with 'black'
 	pipenv run black .
 
-ruff-apply: # resolve 'fixable errors' with 'ruff'
+ruff-apply: # Resolve 'fixable errors' with 'ruff'
 	pipenv run ruff check --fix .

README.md

@@ -2,7 +2,7 @@
 
 A template repository for creating Python lambda functions.
 
-## Repo setup (delete this section and above after initial function setup)
+## Repo Setup (delete this section and above after initial function setup)
 
 1. Rename "my_function" to the desired initial function name across the repo. (May be helpful to do a project-wide find-and-replace).
 2. Update Python version if needed (note: AWS lambda cannot currently support versions higher than 3.9).
@@ -32,12 +32,7 @@ Description of the function/functions.
 - To run unit tests: `make test`
 - To lint the repo: `make lint`
 
-## Required ENV
-
-- `SENTRY_DSN` = If set to a valid Sentry DSN, enables Sentry exception monitoring. This is not needed for local development.
-- `WORKSPACE` = Set to `dev` for local development, this will be set to `stage` and `prod` in those environments by Terraform.
-
-## Running locally
+## Running Locally with Docker
 
 <https://docs.aws.amazon.com/lambda/latest/dg/images-test.html>
 
@@ -65,10 +60,27 @@ Description of the function/functions.
   "You have successfully called this lambda!"
   ```
 
-## Running a different handler in the container
+## Running a Specific Handler Locally with Docker
 
 If this repo contains multiple lambda functions, you can call any handler you copy into the container (see Dockerfile) by name as part of the `docker run` command:
 
 ```bash
 docker run -p 9000:8080 my_function:latest lambdas.<a-different-module>.lambda_handler
 ```
+
+## Environment Variables
+
+### Required
+
+```shell
+SENTRY_DSN=### If set to a valid Sentry DSN, enables Sentry exception monitoring. This is not needed for local development.
+WORKSPACE=### Set to `dev` for local development, this will be set to `stage` and `prod` in those environments by Terraform.
+```
+
+### Optional
+
+_Delete this section if it isn't applicable to the PR._
+
+```shell
+<OPTIONAL_ENV>=### Description for optional environment variable
+```