Update .gitattributes (#770)

Author: rvitaliy

.gitattributes

@@ -1,3 +1,24 @@
-/examples export-ignore
-/docs export-ignore
+# Auto-detect text files, ensure they use LF.
+*       text=auto eol=lf
+
+# These files are always considered text and should use LF.
+# See core.whitespace @ http://git-scm.com/docs/git-config for whitespace flags.
+*.php   text eol=lf whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4 diff=php
+*.json  text eol=lf whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4
+*.yml   text eol=lf whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4
+*.md    text eol=lf whitespace=blank-at-eol,blank-at-eof
+*.rst   text eol=lf whitespace=blank-at-eol,blank-at-eof
+
+# Exclude non-essential files from dist
 /tests export-ignore
+/.appveyor.yml export-ignore
+/.craft.yml export-ignore
+/.editorconfig export-ignore
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/.php_cs export-ignore
+/.scrutinizer.yml export-ignore
+/.travis.yml export-ignore
+/Makefile export-ignore
+/phpstan.neon export-ignore
+/phpunit.xml.dist export-ignore