Improve static_dir documentation

* It was still written for From Source installs. Now it's both OTP and From Source
* I linked to the cheatsheet where it was about configuration
* I moved the mix tasks of the robot.txt section to the CLI tasks and linked to it
    * i checked the code at https://git.pleroma.social/pleroma/pleroma/-/blob/develop/lib/mix/tasks/pleroma/robotstxt.ex and it doesn't seem to more than just this one command with this option
* I also added the location of robot.txt and an example to dissallow everything, but allow the fediverse.network crawlers
* The Thumbnail section still linked to distsn.org which doesn't exist any more. I changed it to a general statemant that it can be used by external applications. (I don't know any that actually use it.)
* Both the logo and TOS need an extra `static` folder. I've seen confusion about that in #pleroma so I added an Important note.

1 files changed, 17 insertions, 0 deletions

diff --git a/docs/administration/CLI_tasks/robots_txt.md b/docs/administration/CLI_tasks/robots_txt.md
new file mode 100644
index 000000000..b1de0981b
--- /dev/null
+++ b/docs/administration/CLI_tasks/robots_txt.md
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+# Managing robot.txt
+
+{! backend/administration/CLI_tasks/general_cli_task_info.include !}
+
+## Generate a new robot.txt file and add it to the static directory
+
+The `robots.txt` that ships by default is permissive. It allows well-behaved search engines to index all of your instance's URIs.
+
+If you want to generate a restrictive `robots.txt`, you can run the following mix task. The generated `robots.txt` will be written in your instance [static directory](../../../configuration/static_dir/).
+
+```elixir tab="OTP"
+./bin/pleroma_ctl robots_txt disallow_all
+```
+
+```elixir tab="From Source"
+mix pleroma.robots_txt disallow_all
+```