Add back appinfo/info.xml

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

appinfo/info.xml

+<?xml version="1.0"?>
+<info xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance"
+      xsi:noNamespaceSchemaLocation="https://apps.nextcloud.com/schema/apps/info.xsd">
+	<id>mail</id>
+	<name>Mail</name>
+	<summary>IMAP web client</summary>
+	<description>Easy to use email client which connects to your mail server via IMAP and SMTP.</description>
+	<version>0.10.0</version>
+	<licence>agpl</licence>
+	<author>Christoph Wurst</author>
+	<author>Jan-Christoph Borchardt</author>
+	<author>Steffen Lindner</author>
+	<namespace>Mail</namespace>
+	<documentation>
+		<admin>https://github.com/nextcloud/mail#readme</admin>
+	</documentation>
+	<category>social</category>
+	<category>office</category>
+	<website>https://github.com/nextcloud/mail#readme</website>
+	<bugs>https://github.com/nextcloud/mail/issues</bugs>
+	<repository type="git">https://github.com/nextcloud/mail.git</repository>
+	<screenshot>https://raw.githubusercontent.com/nextcloud/mail/74e94da16618b32ee0834e57bbfc83ff7334f709/screenshots/mail.png</screenshot>
+	<dependencies>
+		<php min-version="7.0" max-version="7.2" />
+		<nextcloud min-version="14" max-version="14" />
+	</dependencies>
+	<repair-steps>
+		<post-migration>
+			<step>OCA\Mail\Migration\FixCollectedAddresses</step>
+		</post-migration>
+	</repair-steps>
+	<commands>
+		<command>OCA\Mail\Command\CreateAccount</command>
+		<command>OCA\Mail\Command\ExportAccount</command>
+	</commands>
+</info>