add source eth_erd_hu (#1344)

doc/source/eth_erd_hu.md

@@ -0,0 +1,41 @@
+# ÉTH (Érd, Diósd, Nagytarcsa, Sóskút, Tárnok)
+
+Support for schedules provided by [ÉTH](https://www.eth-erd.hu/hulladeknaptar), serving Diósd, Érd, Nagytarcsa, Sóskút, Tárnok, HU.
+
+## Configuration via configuration.yaml
+
+```yaml
+waste_collection_schedule:
+  sources:
+    - name: eth_erd_hu
+      args:
+        city: CITY_NAME
+        street: FULL_STREET_NAME
+        house_number: HOUSE_NUMBER
+```
+
+### Configuration Variables
+
+**CITY**
+*(string) (required)*
+
+**STREET**
+*(string) (required)*
+without "utca", "út", etc.
+not required in Sóskút
+
+**HOUSE_NUMBER**
+*(number) (required)*
+not required in Sóskút
+
+## Example
+
+```yaml
+waste_collection_schedule:
+  sources:
+    - name: eth_erd_hu
+      args:
+        city: Diósd
+        street: Diófasor
+        house_number: 10
+```