Create folder "admin" and add to it the V6 Feature Tracking Log (#13)

* Create v6-feature-tracker.md

* Update v6-feature-tracker.md

Author: RexJaeschke

admin/v6-feature-tracker.md

@@ -0,0 +1,27 @@
+## V6 Feature List and Current Status
+
+To find out what was new/different in v6, Rex used two main sources:
+
+- The [What's New in V6](https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-6) web page
+- The diffs that resulted when he compared the v5std md with the v6spec md.
+
+In the latter case, he located those features that required new or changed grammar. He then found all uses of the names of grammar productions that were added/removed, so he could make adjustments to the text. As he progressed, he discovered some new features that did *not* involve grammar changes. Others have reported (small) new features as well.
+
+This file identifies the known V6 features and tracks their status.
+
+Feature | PR | Notes
+-------- | --- | ----------
+initialization of an accessible indexer  | [??](https://github.com/ECMA-TC49-TG2/conversion-to-markdown/pull/87), [??](https://github.com/ECMA-TC49-TG2/conversion-to-markdown/pull/114) | This also handled the initialization of associative collections using indexers
+expression-bodied function members | [4](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/4) | The "What's New" page only mentions methods and properties; however, the final edits also included indexers and operators as well. As a by-product, this PR also took care of adding support for automatically implemented property initializers
+read-only automatically implemented properties | [11](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/11) | 
+using static |  [9](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/9) |
+nameof | [10](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/10) |
+exception filter |  [2](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/2) |
+null-conditional operator | [7](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/7) |
+interpolated strings | [12](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/12) |
+enum base type tweak |  [??](https://github.com/ECMA-TC49-TG2/conversion-to-markdown/pull/111) | See [here](https://github.com/dotnet/csharplang/blob/master/proposals/csharp-6.0/enum-base-type.md)
+relaxed rules for auto-properties in structs |  [??](https://github.com/ECMA-TC49-TG2/conversion-to-markdown/pull/112) | See [here](https://github.com/dotnet/csharplang/blob/master/proposals/csharp-6.0/struct-autoprop-init.md)
+await in catch and finally blocks | [3](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/3) |
+extension Add methods in collection initializers | [8](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/8) |
+improved overload resolution | [6](https://github.com/ECMA-TC49-TG2/csharpstandard/pull/6) | See Issue #995 
+empty array for params parameter | | See Issue #1004