refac(structure): remove leading gitea directory

The following pull request removes the `gitea` directory. With regard to
maintaining act_runners in a separate git repository or helm chart, this
additional directory becomes redundant.

templates/serviceaccount.yaml

@@ -0,0 +1,21 @@
+{{- if .Values.serviceAccount.create }}
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ include "gitea.serviceAccountName" . }}
+  namespace: {{ .Values.namespace | default .Release.Namespace }}
+  labels:
+    {{- include "gitea.labels" . | nindent 4 }}
+    {{- with .Values.serviceAccount.labels }}
+    {{- . | toYaml | nindent 4 }}
+  {{- end }}
+  {{- with .Values.serviceAccount.annotations }}
+  annotations:
+    {{- . | toYaml | nindent 4 }}
+  {{- end }}
+automountServiceAccountToken: {{ .Values.serviceAccount.automountServiceAccountToken }}
+{{- with .Values.serviceAccount.imagePullSecrets }}
+imagePullSecrets:
+  {{- . | toYaml | nindent 2 }}
+{{- end }}
+{{- end }}