Refactor links, fix markdown

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

_snippets/common-links.md

@@ -40,4 +40,4 @@
 [tfa-dex-static]:   /ha-docker-swarm/traefik-forward-auth/dex-static/
 [tfa-google]:       /ha-docker-swarm/traefik-forward-auth/google/
 [tfa-keycloak]:     /ha-docker-swarm/traefik-forward-auth/keycloak/
-[tfa]:              /ha-docker-swarm/traefik-forward-auth/
+[tfa]:              /ha-docker-swarm/traefik-forward-auth/

_snippets/work-with-me.md

@@ -0,0 +1,7 @@
+Need some Cloud / Microservices / DevOps / Infrastructure design work done? I'm a full-time [AWS Certified Solution Architect (Professional)][cert_aws], a [CNCF-Certified Kubernetes Administrator][cert_cka], [Application Developer][cert_ckad] and [Security Specialist][cert_cks] - this stuff is my bread and butter! :bread: :fork_and_knife: [Get in touch][contact], and let's talk business!
+
+[cert_aws]:         https://www.credly.com/badges/a0c4a196-55ab-4472-b46b-b610b44dc00f
+[cert_cka]:         https://www.credly.com/badges/cd307d51-544b-4bc6-97b0-9015e40df40d
+[cert_ckad]:        https://www.credly.com/badges/9ed9280a-fb92-46ca-b307-8f74a2cccf1d
+[cert_cks]:         https://www.credly.com/badges/93fa53da-1f38-47a9-b6ee-dce6a8fad9fc
+[contact]:          https://www.funkypenguin.co.nz/contact