Document the file structure

Fixes #175

help/en/file_structure.myco

@@ -0,0 +1,19 @@
+= File structure
+//This article is intended for wiki administrators.//
+
+Every Mycorrhiza wiki is stored in one directory. This document explaints the structure of this directory, what files can be there, and what you should do with them.
+
+You can edit all of the files manually, if you want, just do your best to not break anything.
+
+* `config.ini` is the [[/help/en/config_file | configuration file]]. It has comments in it, feel free to edit it.
+* `wiki.git/` is the Git repository of the wiki, it has all hyphae in it. You can edit it directly, but do not forget to make Git commits with your changes and [[/reindex]] you wiki afterwards.
+* `static` holds static data. You can access data there from your wiki with addresses like `/static/image.png`.
+** `static/favicon.ico` is your wiki's favicon, accessed at [[/favicon.ico]] by browsers.
+** `static/common.css` redefines the engine's default style, if exists. You probably don't need to use it.
+** `static/custom.css` is loaded after the main style. If you want to make visual changes to your wiki, this is probably where you should do that.
+* `categories.json` contains the information about all categories in your wiki.
+* `users.json` stores users' information. The passwords are not stored, only their hashes are, this is safe. Their tokens are stored in `cache/tokens.json`.
+* `interwiki.json` holds the interwiki configuration.
+* `cache/` holds cached data. If you back up your wiki, you can omit this directory.
+** `cache/tokens.json` holds users' tokens. By deleting specific tokens, you can log out users remotely.
+* Mycomarkup migration markers are hidden files prefixed with `.mycomarkup-`. You should probably not touch them.

help/view_help.html

@@ -16,7 +16,7 @@ <h2 class="layout-card__title">{{block "topics" .}}Help topics{{end}}</h2>
 		<li><a href="/help/en">{{block "main" .}}Main{{end}}</a></li>
 		<li><a href="/help/en/hypha">{{block "hypha" .}}Hypha{{end}}</a>
 			<ul>
-                <a href="/help/en/media">{{block "media" .}}Media{{end}}</a>
+                <li><a href="/help/en/media">{{block "media" .}}Media{{end}}</a></li>
 			</ul>
 		</li>
 		<li><a href="/help/en/mycomarkup">{{block "mycomarkup" .}}Mycomarkup{{end}}</a></li>
@@ -42,6 +42,7 @@ <h2 class="layout-card__title">{{block "topics" .}}Help topics{{end}}</h2>
 				<li><a href="/help/en/whitelist">{{block "whitelist" .}}Whitelist{{end}}</a></li>
 				<li><a href="/help/en/telegram">{{block "telegram" .}}Telegram authentication{{end}}</a></li>
 				<li><a href="/help/en/interwiki">{{block "interwiki" .}}Interwiki{{end}}</a></li>
+				<li><a href="/help/en/file_structure">{{block "file structure" .}}File structure{{end}}</a></li>
 			</ul>
 		</li>
 	</ul>

help/web.go

@@ -40,6 +40,7 @@ var (
 {{define "whitelist"}}Белый список{{end}}
 {{define "telegram"}}Вход через Телеграм{{end}}
 {{define "interwiki"}}Интервики{{end}}
+{{define "file structure"}}Файловая структура{{end}}
 `
 )