[vcpkg manifest] Add documentation! (#13488)

* [vcpkg docs] add docs for manifest files

These are just for the maintainer docs,
not user docs.

* [vcpkg] EBNF-ify platform expression parsing

this modifies nothing about what strings are accepted or rejected,
it just moves stuff around.

also adds tests.

* [vcpkg docs] add manifest mode example

* [wip] docs for augustin

also fix tabs

* [vcpkg manifest] switch to using maps for features

* Apply suggestions from code review

* un-experimentize format-manifest

* flesh out the user manifest mode docs

* CRs

* billy CRs

* final personal pass-thru

1 files changed, 5 insertions, 8 deletions

diff --git a/ports/blend2d/vcpkg.json b/ports/blend2d/vcpkg.json
index d61e3f4ce..4e763f595 100644
--- a/ports/blend2d/vcpkg.json
+++ b/ports/blend2d/vcpkg.json
@@ -10,18 +10,15 @@
     "logging",
     "tls"
   ],
-  "features": [
-    {
-      "name": "jit",
+  "features": {
+    "jit": {
       "description": "Default feature. Enables jit pipeline compilation. Not supported for ARM and UWP."
     },
-    {
-      "name": "logging",
+    "logging": {
       "description": "Default feature. Enables logging."
     },
-    {
-      "name": "tls",
+    "tls": {
       "description": "Default feature. Enables use of thread_local feature. Disable for platforms where thread local storage is expensive or not supported."
     }
-  ]
+  }
 }