fix the concept exercises metadata (exercism#1118)

* fix the concept exercises metadata

- `blurb` is for `concepts/` documentation not concept exercises
- each needs a name. I didn't feel creative so just capitalized the
existing slug

* fix indentation

config.json

@@ -19,6 +19,7 @@
       {
         "slug": "entry-api",
         "uuid": "e7d8603e-97a9-11ea-9753-0242ac110002",
+        "name": "Entry API",
         "concepts": [
           "entry-api"
         ],
@@ -33,6 +34,7 @@
       {
         "slug": "numbers",
         "uuid": "b042200f-5bdd-4010-981e-626e40fd2877",
+        "name": "Numbers",
         "concepts": [
           "integers",
           "floating-point-numbers"
@@ -44,6 +46,7 @@
       },
       {
         "slug": "enums",
+        "name": "Enums",
         "uuid": "1924b87a-9246-456f-8fc1-111f922a8cf3",
         "concepts": [
           "enums-basic"
@@ -54,6 +57,7 @@
       {
         "slug": "structs",
         "uuid": "3da2420e-9de3-42e0-9127-5ef185673dbb",
+        "name": "Structs",
         "concepts": [
           "structs"
         ],
@@ -67,6 +71,7 @@
       {
         "slug": "options",
         "uuid": "2445b061-6622-47cb-a7ef-9040ec02458c",
+        "name": "Option",
         "concepts": [
           "option"
         ],
@@ -91,8 +96,7 @@
       },
       {
         "slug": "vec-macro",
-        "name": "vec-macro",
-        "blurb": "Rust macros come in handy for creating vectors.",
+        "name": "The Vec Macro",
         "uuid": "c481e318-ddd7-4f8a-91eb-dadb7315e304",
         "concepts": [
           "vec-macro"