FE part of BE issue 1586 provide index md

• I added an index.md which will be the landing page for the docs. It has an explanation of Pleroma-FE from the user point of view
• See also BE MR: pleroma!2669 (merged)
• And issue: pleroma#1586 (closed)

docs/index.md

+# Introduction to Pleroma-FE
+## What is Pleroma-FE?
+
+Pleroma-FE is the default user-facing frontend for Pleroma. If your instance uses Pleroma-FE, you can acces it by going to your instance (e.g. <https://pleroma.soykaf.com>). At this point you will have two columns in front of you.
+
+### Left column
+
+- first block: this section is dedicated to posting:
+    - You can see your avatar and nickname. Clicking your profile pic will open your profile.
+    - Under that you have a text form which allows you to post new statuses. The number on the bottom of the text form is a character counter, every instance can have a different character limit, but the default is 5000.
+    - If you want to mention someone, type @ + name of the person. A drop-down menu will help you in finding the right person.
+    - Under the text form there are also several visibility options and there is the option to use rich text.
+    - Under that the icon on the left is for uploading media files and attach them to your post. There is also an emoji-picker and an option to post a poll.
+    - To post your status, simply press Submit.
+
+- second block: Here you can switch between the different timelines:
+    - Timeline: all the people that you follow
+    - Interactions: here you can switch between different timelines where there was interaction with your account. There is Mentions, Repeats and Favorites, and New follows
+    - Direct Messages: these are the Direct Messages sent to you
+    - Chats: Here you can choose people to chat with. At the moment chats are one-on-one, but in the future it will become possible to chat with a group as well.
+    - Public Timeline: all the statutes from the local instance
+    - The Whole Known Network: all public posts the instance knows about, both local and remote!
+    - About: This isn't a Timeline but shows relevant info about the instance. You can find a list of the moderators and admins, Terms of Service, MRF policies and enabled features.
+- Optional third block: This is the Instance panel that can be activated, but is deactivated by default. It's fully customisable and by default has links to the pleroma-fe and Mastodon-fe.
+- fourth block: This is the Notifications block, here you will get notified whenever somebody mentions you, follows you, repeats or favorites one of your statuses.
+
+### Right column
+This is where the interesting stuff happens!
+Depending on the timeline you will see different statuses, but each status has a standard structure:
+
+- Profile pic, name and link to profile. An optional left-arrow if it's a reply to another status (hovering will reveal the reply-to status). Clicking on the profile pic will uncollapse the user's profile.
+- A `+` button on the right allows you to Expand/Collapse an entire discussion thread. It also updates in realtime!
+- An arrow icon allows you to open the status on the instance where it's originating from.
+- The text of the status, including mentions and attachements. If you click on a mention, it will automatically open the profile page of that person.
+- Four buttons (left to right): Reply, Repeat, Favorite and Add Reaction. There is also a forth button, this is a dropdown menu for simple moderation like muting the conversation or, if you have moderation rights, delete the status from the server.
+
+### Top right
+
+- The magnifier icon opens the search screen
+    - You can search for statuses, people and hashtags.
+    - You can import statusses from remote servers by pasting the url to the post in the search field.
+    - If you want to search for users that your instance doesn't know about yet, you can search for them using the full `name@instance.tld` form. You can also use the full url from their remote profile.
+- The gear icon gives you settings
+- If you have admin rights, you'll see an icon that opens the admin interface
+- The last icon is to log out
+
+### Bottom right
+On the bottom right you have a chatbox. Here you can communicate with people on the same instance in realtime. It is local-only and will most probably be removed once the Chats functionality will allow group chats.