ARROW-295: [Documentation] Add DOAP file

Hi,

Went to have a look at the [Apache Project listing](https://projects.apache.org/projects.html?language) and couldn't find Arrow there, so quickly grabbed Avro's DOAP, compared with a few Commons' DOAP files, and here's the result.

Notes:

- Use GitHub instead of git-wip (as far as I know, [git-wip is EOL](https://blogs.apache.org/infra/entry/relocation-of-apache-git-repositories), and all projects have to migrate to GitBox).
- Couldn't find a Wikipedia page for Arrow. That's where I normally find when the project was created, so used the [TLP project announcement](https://blogs.apache.org/foundation/entry/the_apache_software_foundation_announces87) date for the project `created` value.
- Use README's list of programming languages to create the list in this DOAP file.
- Some projects include updating DOAP release notes during/after the release, but it is not mandatory, and some (most?) ASF projects have outdated dates for the release in their DOAP files... having a DOAP file with valid metadata is still useful.

Happy to update branch it if necessary.

Other comments:

- Validated with W3C RDF validator, looks OK
- Built site locally and pushed to my fork to test that the DOAP file appeared correctly in the [browser](https://kinow.github.io/arrow/arrow.rdf). Basically, by having the file in the `site` directory and not including it in the `_config.yaml` to be excluded seems to be enough
- If/once merged, the ASF project listing would still lack Arrow. That's because someone (a PMC or committer) still needs to follow the [documentation for projects](https://projects.apache.org/create.html) and updated the [ASF SVN XML](https://svn.apache.org/repos/asf/comdev/projects.apache.org/trunk/data/projects.xml) used. But that's just one line, pointing to http://arrowapache.org/arrow.rdf

Cheers
Bruno

Author: Bruno P. Kinoshita <kinow@users.noreply.github.com>

Closes #3307 from kinow/add-doap-file and squashes the following commits:

d92566e9f <Bruno P. Kinoshita> ARROW-295: Add Matlab, and update release date/version
2c8b23ef9 <Bruno P. Kinoshita> ARROW-295: add DOAP file
diff --git a/arrow.rdf b/arrow.rdf
new file mode 100644
index 0000000..9ec078f
--- /dev/null
+++ b/arrow.rdf
@@ -0,0 +1,62 @@
+<?xml version="1.0"?>
+<?xml-stylesheet type="text/xsl"?>
+<rdf:RDF xml:lang="en"
+         xmlns="http://usefulinc.com/ns/doap#"
+         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+         xmlns:asfext="http://projects.apache.org/ns/asfext#"
+         xmlns:foaf="http://xmlns.com/foaf/0.1/">
+<!--
+    Licensed to the Apache Software Foundation (ASF) under one or more
+    contributor license agreements.  See the NOTICE file distributed with
+    this work for additional information regarding copyright ownership.
+    The ASF licenses this file to You under the Apache License, Version 2.0
+    (the "License"); you may not use this file except in compliance with
+    the License.  You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+-->
+  <Project rdf:about="https://arrow.apache.org">
+    <created>2016-02-17</created>
+    <license rdf:resource="http://usefulinc.com/doap/licenses/asl20" />
+    <name>Apache arrow</name>
+    <homepage rdf:resource="http://arrow.apache.org/" />
+    <asfext:pmc rdf:resource="http://arrow.apache.org" />
+    <shortdesc>Apache Arrow is a cross-language development platform for in-memory data.</shortdesc>
+    <description>Apache Arrow is a cross-language development platform for in-memory data.</description>
+    <bug-database rdf:resource="https://issues.apache.org/jira/browse/ARROW" />
+    <mailing-list rdf:resource="http://mail-archives.apache.org/mod_mbox/arrow-dev/" />
+    <download-page rdf:resource="http://arrow.apache.org/release/" />
+    <programming-language>C</programming-language>
+    <programming-language>C++</programming-language>
+    <programming-language>C#</programming-language>
+    <programming-language>Go</programming-language>
+    <programming-language>Java</programming-language>
+    <programming-language>JavaScript</programming-language>
+    <programming-language>MATLAB</programming-language>
+    <programming-language>Python</programming-language>
+    <programming-language>R</programming-language>
+    <programming-language>Ruby</programming-language>
+    <programming-language>Rust</programming-language>
+    <category rdf:resource="http://projects.apache.org/category/library" />
+    <category rdf:resource="http://projects.apache.org/category/big-data" />
+    <release>
+      <Version>
+        <name>Apache Arrow</name>
+        <created>2019-01-20</created>
+        <revision>0.12.0</revision>
+      </Version>
+    </release>
+    <repository>
+      <GitRepository>
+        <location rdf:resource="https://github.com/apache/arrow.git"/>
+        <browse rdf:resource="https://github.com/apache/arrow/"/>
+      </GitRepository>
+    </repository>
+  </Project>
+</rdf:RDF>