use subcommands in plugin updaters (#223164)

* update.py: introduce subparsers for plugin updaters

This is preliminary work to help create more powerful plugin updaters.
Namely I would like to be able to "just add" plugins without refreshing
the older ones (helpful when github temporarily removes a user from
github due to automated bot detection).

Also concerning the lua updater, we pin some of the dependencies, and I
would like to be able to unpin the package without editing the csv
(coming in later PRs).

* doc/updaters: update command to update editor plugins

including vim, kakoune and lua packages

Co-authored-by: figsoda

doc/languages-frameworks/lua.section.md

@@ -129,16 +129,21 @@ Let's present the luarocks way first and the manual one in a second time.
 ### Packaging a library on luarocks {#packaging-a-library-on-luarocks}
 
 [Luarocks.org](https://luarocks.org/) is the main repository of lua packages.
-The site proposes two types of packages, the rockspec and the src.rock
+The site proposes two types of packages, the `rockspec` and the `src.rock`
 (equivalent of a [rockspec](https://github.com/luarocks/luarocks/wiki/Rockspec-format) but with the source).
-These packages can have different build types such as `cmake`, `builtin` etc .
 
-Luarocks-based packages are generated in pkgs/development/lua-modules/generated-packages.nix from
-the whitelist maintainers/scripts/luarocks-packages.csv and updated by running maintainers/scripts/update-luarocks-packages.
+Luarocks-based packages are generated in [pkgs/development/lua-modules/generated-packages.nix](https://github.com/NixOS/nixpkgs/tree/master/pkgs/development/lua-modules/generated-packages.nix) from
+the whitelist maintainers/scripts/luarocks-packages.csv and updated by running
+the script
+[maintainers/scripts/update-luarocks-packages](https://github.com/NixOS/nixpkgs/tree/master/maintainers/scripts/update-luarocks-packages):
+
+```sh
+./maintainers/scripts/update-luarocks-packages update
+```
 
 [luarocks2nix](https://github.com/nix-community/luarocks) is a tool capable of generating nix derivations from both rockspec and src.rock (and favors the src.rock).
 The automation only goes so far though and some packages need to be customized.
-These customizations go in `pkgs/development/lua-modules/overrides.nix`.
+These customizations go in [pkgs/development/lua-modules/overrides.nix](https://github.com/NixOS/nixpkgs/tree/master/pkgs/development/lua-modules/overrides.nix).
 For instance if the rockspec defines `external_dependencies`, these need to be manually added to the overrides.nix.
 
 You can try converting luarocks packages to nix packages with the command `nix-shell -p luarocks-nix` and then `luarocks nix PKG_NAME`.

doc/languages-frameworks/vim.section.md

@@ -212,7 +212,7 @@ Note: this is not possible anymore for Neovim.
 
 ## Adding new plugins to nixpkgs {#adding-new-plugins-to-nixpkgs}
 
-Nix expressions for Vim plugins are stored in [pkgs/applications/editors/vim/plugins](https://github.com/NixOS/nixpkgs/tree/master/pkgs/applications/editors/vim/plugins). For the vast majority of plugins, Nix expressions are automatically generated by running [`./update.py`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/update.py). This creates a [generated.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/generated.nix) file based on the plugins listed in [vim-plugin-names](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/vim-plugin-names). Plugins are listed in alphabetical order in `vim-plugin-names` using the format `[github username]/[repository]@[gitref]`. For example https://github.com/scrooloose/nerdtree becomes `scrooloose/nerdtree`.
+Nix expressions for Vim plugins are stored in [pkgs/applications/editors/vim/plugins](https://github.com/NixOS/nixpkgs/tree/master/pkgs/applications/editors/vim/plugins). For the vast majority of plugins, Nix expressions are automatically generated by running [`./update.py`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/update.py). This creates a [generated.nix](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/generated.nix) file based on the plugins listed in [vim-plugin-names](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/vim-plugin-names).
 
 After running `./update.py`, if nvim-treesitter received an update, also run [`nvim-treesitter/update.py`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/vim/plugins/update.py) to update the tree sitter grammars for `nvim-treesitter`.
 
@@ -226,7 +226,7 @@ deoplete-fish = super.deoplete-fish.overrideAttrs(old: {
 
 Sometimes plugins require an override that must be changed when the plugin is updated. This can cause issues when Vim plugins are auto-updated but the associated override isn't updated. For these plugins, the override should be written so that it specifies all information required to install the plugin, and running `./update.py` doesn't change the derivation for the plugin. Manually updating the override is required to update these types of plugins. An example of such a plugin is `LanguageClient-neovim`.
 
-To add a new plugin, run `./update.py --add "[owner]/[name]"`. **NOTE**: This script automatically commits to your git repository. Be sure to check out a fresh branch before running.
+To add a new plugin, run `./update.py add "[owner]/[name]"`. **NOTE**: This script automatically commits to your git repository. Be sure to check out a fresh branch before running.
 
 Finally, there are some plugins that are also packaged in nodePackages because they have Javascript-related build steps, such as running webpack. Those plugins are not listed in `vim-plugin-names` or managed by `update.py` at all, and are included separately in `overrides.nix`. Currently, all these plugins are related to the `coc.nvim` ecosystem of the Language Server Protocol integration with Vim/Neovim.