Rename doc/manual{src -> source}

This is needed to avoid this
https://github.com/mesonbuild/meson/issues/13774 when we go back to
making our subproject directory `src`.

doc/manual/source/command-ref/nix-store/import.md

@@ -0,0 +1,43 @@
+# Name
+
+`nix-store --import` - import [Nix Archive] into the store
+
+[Nix Archive]: @docroot@/store/file-system-object/content-address.md#serial-nix-archive
+
+# Synopsis
+
+`nix-store` `--import`
+
+# Description
+
+The operation `--import` reads a serialisation of a set of [store objects](@docroot@/glossary.md#gloss-store-object) produced by [`nix-store --export`](./export.md) from standard input, and adds those store objects to the specified [Nix store](@docroot@/store/index.md).
+Paths that already exist in the target Nix store are ignored.
+If a path [refers](@docroot@/glossary.md#gloss-reference) to another path that doesn’t exist in the target Nix store, the import fails.
+
+> **Note**
+>
+> For efficient transfer of closures to remote machines over SSH, use [`nix-copy-closure`](@docroot@/command-ref/nix-copy-closure.md).
+
+{{#include ./opt-common.md}}
+
+{{#include ../opt-common.md}}
+
+{{#include ../env-common.md}}
+
+# Examples
+
+> **Example**
+>
+> Given a closure of GNU Hello as a file:
+>
+> ```shell-session
+> $ storePath="$(nix-build '<nixpkgs>' -I nixpkgs=channel:nixpkgs-unstable -A hello --no-out-link)"
+> $ nix-store --export $(nix-store --query --requisites $storePath) > hello.closure
+> ```
+>
+> Import the closure into a [remote SSH store](@docroot@/store/types/ssh-store.md) using the [`--store`](@docroot@/command-ref/conf-file.md#conf-store) option:
+>
+> ```console
+> $ nix-store --import --store ssh://alice@itchy.example.org < hello.closure
+> ```
+