Create swift package

.swiftformat

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+# .swiftformat
+
+## file options
+
+--exclude .build,.github,.swiftpm,.vscode,Configurations,Dependencies
+
+## format options
+
+--allman false
+--binarygrouping 4,8
+--commas always
+--comments indent
+--decimalgrouping 3,6
+--elseposition same-line
+--empty void
+--exponentcase lowercase
+--exponentgrouping disabled
+--fractiongrouping disabled
+--header ignore
+--hexgrouping 4,8
+--hexliteralcase uppercase
+--ifdef indent
+--importgrouping testable-bottom
+--indent 4
+--indentcase false
+--linebreaks lf
+--maxwidth none
+--octalgrouping 4,8
+--operatorfunc spaced
+--patternlet hoist
+--ranges spaced
+--self remove
+--semicolons inline
+--stripunusedargs always
+--swiftversion 5.1
+--trimwhitespace always
+--wraparguments preserve
+--wrapcollections preserve
+
+## rules
+
+--enable isEmpty,andOperator,assertionFailures