[docs] [pipes] - Add placeholder pages (dagster-io#17057)

## Summary & Motivation

This PR adds placeholder pages for the Dagster Pipes documentation.

## How I Tested These Changes

👀

docs/content/guides/dagster-pipes/customizing-dagster-pipes-protocols.mdx

@@ -0,0 +1,6 @@
+---
+title: "Customizing Dagster Pipes protocols | Dagster Docs"
+description: ""
+---
+
+# Customizing Dagster Pipes protocols

docs/content/guides/dagster-pipes/integrating-databricks-with-dagster-pipes.mdx

@@ -0,0 +1,6 @@
+---
+title: "Integrating Databricks with Dagster Pipes | Dagster Docs"
+description: ""
+---
+
+# Integrating Databricks with Dagster Pipes

docs/content/guides/dagster-pipes/integrating-docker-with-dagster-pipes.mdx

@@ -0,0 +1,6 @@
+---
+title: "Integrating Docker with Dagster Pipes | Dagster Docs"
+description: ""
+---
+
+# Integrating Docker with Dagster Pipes

docs/content/guides/dagster-pipes/integrating-kubernetes-with-dagster-pipes.mdx

@@ -0,0 +1,6 @@
+---
+title: "Integrating Kubernetes with Dagster Pipes | Dagster Docs"
+description: ""
+---
+
+# Integrating Kubernetes with Dagster Pipes

docs/content/guides/dagster-pipes/integrating-subprocess-with-dagster-pipes.mdx

@@ -0,0 +1,6 @@
+---
+title: "Integrating Subprocess with Dagster Pipes | Dagster Docs"
+description: ""
+---
+
+# Integrating Subprocess with Dagster Pipes

docs/content/guides/dagster-pipes/understanding-dagster-pipes.mdx

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+---
+title: "Understanding the Dagster Pipes process | Dagster Docs"
+description: ""
+---
+
+# Understanding the Dagster Pipes process