Update README with new author metadata tags

Author: Cactooz

README.md

@@ -71,7 +71,12 @@ All files are named and contain two sections, YAML front matter first and conten
 The front matter is contained by one line with `---` each before and after the section. Possible fields in the front matter are:
 
 - `title`, the name or title of the song **(required)**
-- `author`, the person or persons who wrote the lyrics of the song
+- `author`, information about the person or persons who wrote the lyrics of the song
+  - `name`, the name of the person or persons who wrote the lyrics of the song
+  - `event`, the event for which the song was made
+  - `location`, the city or university where the song is from
+  - `year`, the year the song was written
+  - `comment`, a comment about the author (for example, if an author wrote one of the verses)
 - `melody`, the melody the song is sung to
 - `composer`, the composer of the melody
 - `tags`, list of categories the songs fall in to and other identifiers (valid tags can be found in [`/src/definitions/tags.ts`](/src/definitions/tags.ts#L1-L12)) **(required)**
@@ -85,7 +90,11 @@ Any field without a value should be omitted.
 ```yml
 ---
 title: Moder Kista
-author: David Larsson, IT00
+author:
+  - name: David Larsson, IT-00
+    event: IT-nØllningen
+    location: KTH
+    year: 2000
 melody: Längtan till landet
 composer: Otto Lindblad
 tags: [gasque, swe]
@@ -169,7 +178,12 @@ Creates a new song with the next possible ID and the given title. Front matter b
 ```yaml
 ---
 title: Moder Kista
-author: David Larsson, IT00
+author:
+  - name: David Larsson, IT00
+    event:
+	location:
+	year:
+	comment:
 melody:
 composer:
 tags: [gasque]
@@ -284,6 +298,12 @@ Fronten har en rad med `---` före och efter sektionen. Möjliga fält i fronten
 
 - `title`, namnet eller titeln på sången **(obligatorisk)**
 - `author`, personen eller personerna som skrev sångtexten
+- `author`, information om personen eller personerna som skrev sångtexten
+  - `name`, personen eller personerna som skrev sångtexten
+  - `event`, evenemanget sången skrevs till
+  - `location`, staden eller universitetet som sången kommer ifrån
+  - `year`, året sången skrevs
+  - `comment`, kommentar om skribenten (exempelvis om en skribent har skrivit en av verserna)
 - `melody`, melodin som sången sjungs i
 - `composer`, kompositör till melodin
 - `tags`, lista med kategorier som sångerna tillhör och andra identifierare (giltiga taggar hittas i [`/src/definitions/tags.ts`](/src/definitions/tags.ts#L1-L12)) **(obligatorisk)**
@@ -297,7 +317,11 @@ Alla fält utan värde bör utelämnas.
 ```yml
 ---
 title: Moder Kista
-author: David Larsson, IT00
+author:
+  - name: David Larsson, IT-00
+    event: IT-nØllningen
+    location: KTH
+    year: 2000
 melody: Längtan till landet
 composer: Otto Lindblad
 tags: [gasque, swe]
@@ -382,7 +406,12 @@ Skapar en ny sång med nästa möjliga ID och den givna titeln. Fronten fylls me
 ```yaml
 ---
 title: Moder Kista
-author: David Larsson, IT00
+author:
+  - name: David Larsson, IT00
+    event:
+	location:
+	year:
+	comment:
 melody:
 composer:
 tags: [gasque]