Restructure quickstart section (#529)

There is no need to know about older versions of Fluentd or td-agent, so move it from quickstart section.

It is still useful for migration, so keep it as appendix section.

NOTE: v1.18.0 still points to ruby 2.7.
In a sooner or later, it will be bumped up to 3.2 in v1.19.0.

Signed-off-by: Kentaro Hayashi <hayashi@clear-code.com>

Author: kenhys

.gitbook.yaml

@@ -9,13 +9,13 @@ redirects:
 
   # Overview
   v1.0/articles/support: overview/support.md
-  v1.0/articles/update-from-v0.12: overview/update-from-v0.12.md
+  v1.0/articles/update-from-v0.12: appendix/update-from-v0.12.md
   v1.0/articles/life-of-a-fluentd-event: overview/life-of-a-fluentd-event.md
   v1.0/articles/logo: overview/logo.md
   v1.0/articles/faq: overview/faq.md
-  v1.0/articles/td-agent-v2-vs-v3: overview/td-agent-v2-vs-v3-vs-v4.md
-  v1.0/articles/fluent-package-v5-vs-td-agent-v4: overview/fluent-package-v5-vs-td-agent.md
-  quickstart/td-agent-v2-vs-v3: overview/td-agent-v2-vs-v3-vs-v4.md
+  v1.0/articles/td-agent-v2-vs-v3: appendix/td-agent-v2-vs-v3-vs-v4.md
+  v1.0/articles/fluent-package-v5-vs-td-agent-v4: quickstart/fluent-package-v5-vs-td-agent.md
+  quickstart/td-agent-v2-vs-v3: appendix/td-agent-v2-vs-v3-vs-v4.md
 
   # Install
   v1.0/articles/install-by-dmg: install/install-by-dmg.md

SUMMARY.md

@@ -3,11 +3,9 @@
 * [Introduction](README.md)
 * [Overview](quickstart/README.md)
   * [Life of a Fluentd event](quickstart/life-of-a-fluentd-event.md)
-  * [Update from v0.12 to v1](quickstart/update-from-v0.12.md)
   * [Support](quickstart/support.md)
   * [FAQ](quickstart/faq.md)
   * [Logo](quickstart/logo.md)
-  * [td-agent v2 vs v3 vs v4](quickstart/td-agent-v2-vs-v3-vs-v4.md)
   * [fluent-package v5 vs td-agent v4](quickstart/fluent-package-v5-vs-td-agent.md)
 * [Installation](installation/README.md)
   * [Before Installation](installation/before-install.md)
@@ -197,4 +195,7 @@
   * [Plugin Helper: Http Server](plugin-helper-overview/api-plugin-helper-http_server.md)
   * [Plugin Helper: Service Discovery](plugin-helper-overview/api-plugin-helper-service_discovery.md)
 * [Troubleshooting Guide](troubleshooting-guide.md)
+* [Appendix](appendix/README.md)
+  * [Update from v0.12 to v1](appendix/update-from-v0.12.md)
+  * [td-agent v2 vs v3 vs v4](appendix/td-agent-v2-vs-v3-vs-v4.md)
 

quickstart/td-agent-v2-vs-v3-vs-v4.md appendix/td-agent-v2-vs-v3-vs-v4.mdquickstart/td-agent-v2-vs-v3-vs-v4.md renamed to appendix/td-agent-v2-vs-v3-vs-v4.md

@@ -1,5 +1,9 @@
 # td-agent v2 vs v3 vs v4
 
+{% hint style='danger' %}
+The series of td-agent had already reached End of Life (EOL). td-agent should not be newly installed because no support, no new release and no security updates anymore.
+{% endhint %}
+
 ## Supported Platforms
 
 [ClearCode, Inc.](https://www.clear-code.com) maintains stable packages for Fluentd and canonical plugins as Treasure Agent \(the package is called `td-agent`\). `td-agent` has v2, v3 and v4. [Chronosphere](https://chronosphere.io/) (formerly Calyptia) maintains stable packages as Calyptia-fluentd as another option. Supported OS is the same as td-agent v4 currently.
@@ -49,10 +53,10 @@ This is for v0.12 and old distribution users. We don't recommend this version fo
 
 ## How to Install
 
-* [Ubuntu/Debian](../installation/install-by-deb.md)
-* [RedHat/CentOS](../installation/install-by-rpm.md)
-* [Windows](../installation/install-by-msi.md)
-* [macOS](../installation/install-by-dmg.md)
+* [Ubuntu/Debian](../installation/install-by-deb-td-agent-v4.md)
+* [RedHat/CentOS](../installation/install-by-rpm-td-agent-v4.md)
+* [Windows](../installation/install-by-msi-td-agent-v4.md)
+* [macOS](../installation/install-by-dmg-td-agent-v4.md)
 * [RubyGems](../installation/install-by-gem.md)
 
 If this article is incorrect or outdated, or omits critical information, please [let us know](https://github.com/fluent/fluentd-docs-gitbook/issues?state=open). [Fluentd](http://www.fluentd.org/) is an open-source project under [Cloud Native Computing Foundation \(CNCF\)](https://cncf.io/). All components are available under under [the Apache License 2.0.](https://www.apache.org/licenses/LICENSE-2.0)

quickstart/update-from-v0.12.md appendix/update-from-v0.12.mdquickstart/update-from-v0.12.md renamed to appendix/update-from-v0.12.md

@@ -8,7 +8,7 @@ Please follow the [Pre-installation Guide](before-install.md) to configure your
 
 ## Step 1: Install Ruby Interpreter
 
-Install Ruby `>= 2.4` on your local environment. In addition, install `ruby-dev` package via Package Manager to build native extension gems.
+Install Ruby `>= 2.7` on your local environment. In addition, install `ruby-dev` package via Package Manager to build native extension gems.
 
 ## Step 2: Install Fluentd Gem
 

installation/install-by-gem.md

@@ -1,5 +1,10 @@
 # fluent-package v5 vs td-agent v4
 
+{% hint style='danger' %}
+The series of td-agent had already reached End of Life (EOL). td-agent should not be newly installed because of no support, no new release and no security updates anymore.
+Use fluent-package instead!
+{% endhint %}
+
 ## Supported Platforms
 
 [Fluentd Project](https://www.fluentd.org) maintains stable packages for Fluentd and canonical plugins as Fluent Package \(the package is called `fluent-package`\)