Update readme (#3)

Update ReadMe

Author: gvenzl

README.md

@@ -1,14 +1,32 @@
 # Oracle SQL Features
 
-## Building
+## Contributing
+
+To contribute a feature to this page, add a new [AsciiDoc](https://asciidoc.org/) (`*.adoc`)
+file into the `features` folder.  
+You can find an AsciiDoc template `feature.adoctemplate` in the `features` folder.
+
+AsciiDoc files can be organized into subfolders.
+
+For more information about the AsciiDoc syntax, see the [AsciiDoc Syntax Quick Reference](https://docs.asciidoctor.org/asciidoc/latest/syntax-quick-reference/).
+
+## Building the website locally
+
+It is encouraged to build the website locally first before pushing to GitHub to
+detect rendering issues or typos before the changes go live.
+
+### Dependencies
 
 1. Install Antora as explained at https://docs.antora.org/antora/latest/install-and-run-quickstart/
-2. Refresh navigation files by invoking
+
+### Build
+
+1. Refresh navigation files by invoking
 ```shell
 $ sh .github/scripts/generate-navigation.sh
 ```
-3. Generate the site using the `local-playbook.yml` file
+1. Generate the site using the `local-playbook.yml` file
 ```sh
 $ antora local-playbook.yml
 ```
-4. Inspect the generated site at `build/site/index.html`
+1. Inspect the generated site at `build/site/index.html`

features/feature.adoctemplate

@@ -0,0 +1,30 @@
+= ###Feature Name###
+:database-version: ###Database version###
+:database-category: ###Category###
+
+Replace this text with a brief feature description.
+
+
+[source,sql]
+[subs="verbatim"]
+----
+###Put your SQL syntax here###
+----
+
+.Result
+[source,sql]
+[subs="verbatim"]
+----
+###Put an example of the SQL syntax here (syntax and output)###
+----
+
+== Benefits
+
+Replace this text with the benefits the feature provides
+
+== Further information
+
+* Introduced: xref:versions:{database-version}/index.adoc[]
+* Availability: ###Oracle Database feature edition availability, use "all editions" if it is not factored###
+* link:###URL Link to the Doc###[Documentation]
+* link:###URL Link to an example###[Example]

features/plsql-function-in-sql.adoc

@@ -46,9 +46,9 @@ SELECT capitalize(name) as name, capitalize(get_domain_name(url)) AS domain_name
   FROM products;
 ----
 
+.Result
 [source,sql]
 [subs="verbatim"]
-.Result
 ----
 SQL> WITH
   2    -- Function to capitalize input string