Add Docker and Gitea workflow configurations for Talks slides deployment

- Introduced .dockerignore to exclude unnecessary files from Docker builds.
- Added build-and-push.yaml workflow for automated image building and Helm chart deployment on changes to specific paths.
- Created Dockerfile for building a static site with Nginx, including configuration for serving slides.
- Established Helm chart structure in talks-slides-dist for managing deployment configurations and resources.
- Removed outdated GitHub Actions workflows to streamline CI/CD processes.

talks-slides-dist/templates/_helpers.tpl

@@ -0,0 +1,41 @@
+{{/*
+Expand the name of the chart.
+*/}}
+{{- define "talks-slides.name" -}}
+{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Create a default fully qualified app name.
+*/}}
+{{- define "talks-slides.fullname" -}}
+{{- if .Values.fullnameOverride }}
+{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- $name := default .Chart.Name .Values.nameOverride }}
+{{- if contains $name .Release.Name }}
+{{- .Release.Name | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
+{{- end }}
+{{- end }}
+{{- end }}
+
+{{/*
+Common labels
+*/}}
+{{- define "talks-slides.labels" -}}
+helm.sh/chart: {{ include "talks-slides.name" . }}-{{ .Chart.Version | replace "+" "_" }}
+app.kubernetes.io/name: {{ include "talks-slides.name" . }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
+app.kubernetes.io/managed-by: {{ .Release.Service }}
+{{- end }}
+
+{{/*
+Selector labels
+*/}}
+{{- define "talks-slides.selectorLabels" -}}
+app.kubernetes.io/name: {{ include "talks-slides.name" . }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+{{- end }}