Update index.html.md to remove spending limits.

Adding spending limits to necessary items that folks need to do their jobs is directly contradicting the ideal of "spend company money like it's your own".

We are given trust and autonomy to buy things and be conscious and careful with what we spend and respect the trust we've been given. If we add max restrictions and partial reimbursements, we are no longer able to have visibility on who is breaking that trust. If people are expected to be mindful, they will learn good habits. Those that don't respect the responsibility and trust they are given should be more visible to the rest of us and appropriately dealt with.

Please check out @kirstenabma's comment here:

https://gitlab.com/gitlab-com/people-ops/General/issues/339#note_152124022