Third Korean l10n work for release-1.15 (#15744)

* Add Link /docs/reference/ in Korean (#15610)
* Translate tasks/debug-application-cluster/resource-usage-monitoring in Korean (#15593)
* Translate tasks/inject-data-application/define-environment-variable-container in Korean (#15606)
* ko: Update outdated files in dev-1.15-ko.3 (#15605)
* Translate home/supported-doc-version in Korean (#15621)
* ko: Update some files in reference/glossary (#15631)
* Translate reference/glossary/cloud-provider.md in Korean (#15685)
* Translate docs/reference/using-api/api-overview in Korean (#15644)
* Translate tasks/debug-application-cluster/resource-metrics-pipeline in Korean (#15665)

Co-Authored-By: June Yi <june.yi@samsung.com>
Co-Authored-By: Seokho <shsongist@gmail.com>
Co-Authored-By: Tim Bannister <tim@scalefactory.com>
Co-authored-by: Yoon <learder@gmail.com>
Co-authored-by: JiMyung Lee <lee.ji.myung@gmail.com>
Co-authored-by: lapee79 <lapee79@gmail.com>
Co-authored-by: Sunghoon Kang <hoon@linecorp.com>
Co-authored-by: Yuk, Yongsu <ysyukr@gmail.com>
Co-authored-by: Lawrence Kay <me@lkaybob.pe.kr>

content/ko/examples/pods/inject/envars.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: envar-demo
+  labels:
+    purpose: demonstrate-envars
+spec:
+  containers:
+  - name: envar-demo-container
+    image: gcr.io/google-samples/node-hello:1.0
+    env:
+    - name: DEMO_GREETING
+      value: "Hello from the environment"
+    - name: DEMO_FAREWELL
+      value: "Such a sweet sorrow"