convert meta and tag directives to TOML frontmatter

command:
```
find * -type f -name '*.md' -execdir perl -MTOML::Tiny=to_toml -C63 -gni -E '%x=();s/\[\[!meta\s+(title|date)="?([^\]"]+?)\s*"?\s*\]\]\s*\n*/$x{$1}=$2;""/eg; s/\[\[!meta\s+stylesheet="?edu"?\s+rel="?stylesheet"?\s*\]\]\n*/$x{taxonomies}{categories}=["education"];""/e; s/\[\[!tag((?:\s+[^\]\s]+)+)\s*\]\]\n*/push @{$x{taxonomies}{tags}}, $1=~m{\S+}g;""/eg; s/\[\[!meta\s+(?:author|name)="?([^\]"]+?)\s*"?\s*\]\]\s*\n*/$x{extra}{author}=$1;""/eg; say "+++"; say to_toml({%x}); say "+++"; say $_' '{}' +
```

1 files changed, 22 insertions, 5 deletions

diff --git a/skole/andersen_eventyrkbh/index.md b/skole/andersen_eventyrkbh/index.md
index 3e493247..047ba5da 100644
--- a/skole/andersen_eventyrkbh/index.md
+++ b/skole/andersen_eventyrkbh/index.md
@@ -1,6 +1,25 @@
-[[!meta title="H.C. Andersens eventyr i København"]]
-[[!meta stylesheet=edu rel=stylesheet]]
-
++++
+date=2019-03-17
+title="H.C. Andersens eventyr i København"
+
+[taxonomies]
+categories=[
+  "education",
+]
+tags=[
+  "historie",
+  "city",
+  "ture",
+  "personer",
+  "tema",
+  "litteratur",
+  "hc_andersen",
+  "guldalder",
+  "1800-tallet",
+  "skole",
+  "danskfag",
+]
++++
 [[!if test="included()" then="""
 {{ img(path="/andersen_eventyrkbh/hcaskorstenskyline.jpg" class="overview" link="/skole/andersen_eventyrkbh") }}
 
@@ -41,6 +60,4 @@ og om gadelivet i det gamle København samt persongalleriet i 1800-tallets midte
 
 """]]
 
-[[!tag historie city ture personer tema litteratur hc_andersen guldalder 1800-tallet skole danskfag]]
 
-[[!meta date="2019-03-17"]]