Add project README file.

Author: Potherca

README.md

@@ -0,0 +1,115 @@
+# Inline `source`
+
+Inline `source`-ed code.
+
+## Installation
+
+The advised installation method is using the [`bpkg` package manager][bpkg], as
+this will allow versioning to be used.
+
+Alternatively, the latest version of this project's main script can be 
+downloaded directly:
+
+```sh
+curl -Lo- https://bpkg.pother.ca/inline-source/dist/inline_source
+chmod +x inline_source
+```
+
+## Usage
+
+This script will output a file for a given path, will all `sourced` files inlined.
+
+```sh
+inline_source <source-file>
+```
+
+For instance, given a file `a.sh` and file `b.sh` like this:
+
+**a.sh**
+```sh
+#!/usr/bin/env bash
+
+echo 'I am file A.'
+
+source 'b.sh.'
+```
+
+**b.sh**
+```sh
+#!/usr/bin/env bash
+
+echo 'I am file B.'
+```
+
+Calling `inline_source a.sh` will output:
+
+```sh
+#!/usr/bin/env bash
+
+echo 'I am file A.'
+
+echo 'I am file B.'
+```
+
+If a script sources files that are not in the `$PATH`, this will need to be 
+resolved before calling `inline_source`:
+
+```sh
+export PATH="${PATH}:/path/to/sources" && inline_source a.sh
+```
+
+All that really happens is that the code of any file that is `sourced` in the
+main script is placed inline.
+
+This allows for a single script to be created for distribution purposes.
+
+For instance, the distribution file in this repo was created by pipe-ing the
+output to a file:
+
+```sh
+inline_source inline_source.sh > dist/inline_source
+```
+
+The script leaves everything "as-is", except for any shebang lines that it might
+find. To clean things up, pipe this script through a formatter, for instance
+[shfmt](https://github.com/mvdan/sh):
+
+```sh
+inline_source inline_source.sh | shfmt -i 2 -ci -s > dist/inline_source
+```
+
+## Development
+
+This repository is set up like this:
+
+```
+    .
+    ├── deps/       <-- Third-party dependencies
+    ├── dist/       <-- Bundled distrubtion script
+    ├── src/        <-- Source files
+    ├── bpkg.json   <-- Package declaration
+    └── README.md   <-- You are here
+```
+
+Dependencies needed by this project are managed through [`bpkg`][bpkg].
+
+To install them (in the `deps/` folder) run:
+
+```sh
+bpkg getdeps
+```
+
+After that, edits can be made to files in the `src/` directory.
+
+Finally, to create a single file containing all the source logic (this time
+using a docker image for `shfmt`), run:
+
+```sh
+bash inline_source.sh inline_source.sh \
+  | docker run -i --rm --volume="$PWD:/mnt" -w /mnt mvdan/shfmt -i 2 -ci -s \
+  > dist/inline_source
+```
+
+This will create a distribution file in the `dist/` directory.
+
+[bpkg]: https://github.com/bpkg/bpkg