Write the Attachment article

I also included a link to the article in the Attachment tab.

help/en/attachment.myco

@@ -0,0 +1,34 @@
+# Attachment
+In hyphae, an **attachment** is some content represented by something that is not [[/help/en/mycomarkup | Mycomarkup]]. Usually, an image, a video, or an audio.
+
+## Supported attachment types
+You can upload any file, but only those listed below will be displayed on the website. You can download unsupported attachments, though.
+
+* **Images:** jpg, gif, png, webp, svg, ico
+* **Video:** ogg, webm, mp4
+* **Audio:** ogg, webm, mp3
+
+## How to add an attachment?
+For non-existent hyphae, upload a file in the //Upload a media// section.
+
+For any hyphae, upload a file in the //Attachment// tab.
+
+## Attachment tab
+Every hypha has the //Attachment// tab. Click it to see what is out there.
+
+You can upload a new file, you can //delete// the attachment (it is called //unattaching//) and see some file stats (size and type).
+
+## On naming hyphae with attachments
+The hypha name should not just copy the file name in most cases. If you are uploading a photo of a rose, do not call it `rose.jpg`, no. Call it `photo of rose` or `rose photo` or whatever. You rarely need to think of file extensions when using Mycorrhiza Wiki.
+
+This is not a rule, of course, just a convention.
+
+## What to put in the text part?
+If a hypha has an attachment, here is what the text part might be about:
+* A textual description or representation of the picture.
+* A transcript of the song.
+* An analysis of the attachment.
+* Some meta data.
+* Things above combined.
+
+The attachment //should not// be an illustration.

help/en/index.myco

@@ -3,6 +3,7 @@ This is Mycorrhiza Wiki built-in documentation.
 Hope you are doing well ☺️
 
 Here are the topics covered by the documentation:
-=> /help/en/hypha Hypha
+* [[/help/en/hypha | Hypha]]
+** [[/help/en/attachment | Attachment]]
 
 Thanks for reading!

views/readers.qtpl

@@ -13,12 +13,12 @@
 {% func AttachmentMenuHTML(rq *http.Request, h *hyphae.Hypha, u *user.User) %}
 {%= NavHTML(rq, h.Name, "attachment") %}
 <div class="layout">
-<main class="main-width">
+<main class="main-width attachment-tab">
 	<h1>Attachment of {%s util.BeautifulName(h.Name) %}</h1>
 	{% if h.BinaryPath == "" %}
-	<p class="warning">This hypha has no attachment, you can upload it here.</p>
+	<p class="explanation">This hypha has no attachment, you can upload it here. <a href="/help/en/attachment" class="shy-link">What are attachments?</a></p>
 	{% else %}
-	<p class="warning">You can manage the hypha's attachment on this page.</p>
+	<p class="explanation">You can manage the hypha's attachment on this page. <a href="/help/en/attachment" class="shy-link">What are attachments?</a></p>
 	{% endif %}
 
 	<section class="amnt-grid">

views/readers.qtpl.go

@@ -57,7 +57,7 @@ func StreamAttachmentMenuHTML(qw422016 *qt422016.Writer, rq *http.Request, h *hy
 //line views/readers.qtpl:14
 	qw422016.N().S(`
 <div class="layout">
-<main class="main-width">
+<main class="main-width attachment-tab">
 	<h1>Attachment of `)
 //line views/readers.qtpl:17
 	qw422016.E().S(util.BeautifulName(h.Name))
@@ -68,13 +68,13 @@ func StreamAttachmentMenuHTML(qw422016 *qt422016.Writer, rq *http.Request, h *hy
 	if h.BinaryPath == "" {
 //line views/readers.qtpl:18
 		qw422016.N().S(`
-	<p class="warning">This hypha has no attachment, you can upload it here.</p>
+	<p class="explanation">This hypha has no attachment, you can upload it here. <a href="/help/en/attachment" class="shy-link">What are attachments?</a></p>
 	`)
 //line views/readers.qtpl:20
 	} else {
 //line views/readers.qtpl:20
 		qw422016.N().S(`
-	<p class="warning">You can manage the hypha's attachment on this page.</p>
+	<p class="explanation">You can manage the hypha's attachment on this page. <a href="/help/en/attachment" class="shy-link">What are attachments?</a></p>
 	`)
 //line views/readers.qtpl:22
 	}