doc: point manual contributing guides to devmode's README (#411326)

There's quite a bit of pingpong redirection with Nixpkgs and NixOS
manual utilities. Since devmode was lacking a README, the descriptive
text is moved there and it's referenced by both manuals.

authored by Alejandro Sánchez Medina and committed by GitHub 60264c48 8c35c2b4

+13 -6
+1 -5
doc/README.md
··· 56 56 57 57 #### `devmode` 58 58 59 - The shell in the manual source directory makes available a command, `devmode`. 60 - It is a daemon, that: 61 - 1. watches the manual's source for changes and when they occur — rebuilds 62 - 2. HTTP serves the manual, injecting a script that triggers reload on changes 63 - 3. opens the manual in the default browser 59 + Use [`devmode`](../pkgs/by-name/de/devmode/README.md) for a live preview when editing the manual. 64 60 65 61 ### Testing redirects 66 62
+3 -1
nixos/doc/manual/contributing-to-this-manual.chapter.md
··· 37 37 /**/.direnv 38 38 ``` 39 39 40 - You might want to also use [`devmode`](https://github.com/NixOS/nixpkgs/blob/master/doc/README.md#devmode) while editing the manual. 40 + ### `devmode` {#sec-contributing-devmode} 41 + 42 + Use [`devmode`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/by-name/de/devmode/README.md) for a live preview when editing the manual. 41 43 42 44 ## Testing redirects {#sec-contributing-redirects} 43 45
+3
nixos/doc/manual/redirects.json
··· 95 95 "sec-contributing-development-env": [ 96 96 "index.html#sec-contributing-development-env" 97 97 ], 98 + "sec-contributing-devmode": [ 99 + "index.html#sec-contributing-devmode" 100 + ], 98 101 "sec-mattermost": [ 99 102 "index.html#sec-mattermost" 100 103 ],
+6
pkgs/by-name/de/devmode/README.md
··· 1 + # `devmode` 2 + 3 + `devmode` is a daemon, that: 4 + 1. watches the manual's source for changes and when they occur — rebuilds 5 + 2. HTTP serves the manual, injecting a script that triggers reload on changes 6 + 3. opens the manual in the default browser