[BUG] The TOC generation make it impossible to respect the style guide (all words beyond the first one are lowercased)

[lestephane]

Describe the bug
There is a style guide at https://github.com/quantummaid/.github/blob/master/StyleGuideDocumentation.md,
which mandates the capitalization of all names, such as Lambda. The problem is that the TOC generation lowercases everything beyond the first word.

Consider the following file listing:

$ tree -P '*.md' -L 1 aws-lambda
aws-lambda
├── 01_TheCaseForLambda.md
├── 02_MinimumViableFunction.md
├── 03_AddingLambdaSupport.md
├── 04_DeployingOurFunction.md
├── 05_UpdatingOurFunction.md
├── 06_CleaningUp.md
...

the produced output is

## Table of contents
<!---[TOC](.)-->
1. [The case for lambda](01_TheCaseForLambda.md)
2. [Minimum viable function](02_MinimumViableFunction.md)
3. [Adding lambda support](03_AddingLambdaSupport.md)
4. [Deploying our function](04_DeployingOurFunction.md)
5. [Updating our function](05_UpdatingOurFunction.md)
6. [Cleaning up](06_CleaningUp.md)
<!---EndOfToc-->

The case for lambda should be The case for Lambda and there is no way for the user to affect capitalization choices. Maybe some sort of markup in the target file would help there.