update readme

README.md

@@ -1,2 +1,83 @@
 # gemini-dl
-CLI downloader for Gemini protocol
+
+CLI downloader for [Gemini protocol](https://geminiprotocol.net), inspired by `wget` and `yt-dlp` tools
+
+At this moment, project under development, some [features](#features) already implemented and testing (send [feedback](https://github.com/YGGverse/gemini-dl/issues) | [PR](https://github.com/YGGverse/gemini-dl/pull))
+
+## Interface
+
+## Components
+
+* [gemini-php](https://github.com/YGGverse/gemini-php) - Client for Gemini protocol
+* [gemtext-php](https://github.com/YGGverse/gemtext-php) - Parser for Gemtext
+* [net-php](https://github.com/YGGverse/net-php) - Network toolkit for URL operations
+* [php-cli-colors](https://github.com/mikeerickson/php-cli-colors) - CLI colors
+
+## Features
+
+* [x] Grab single URL or entire capsule for offline reading
+* [x] Multiple MIME download support
+* [x] Crawler log for every request
+* [ ] Flexible options
+  * [x] Custom delay between requests
+  * [x] Custom index filename for directories
+  * [x] Custom storage location
+    * [x] Filesystem
+    * [ ] FTP
+  * [x] Optional URL replacement to relative URI
+  * [x] Recursive crawler
+  * [x] Regex URL rules
+  * [x] Unique snap version support or sync by default
+  * [ ] Configurable redirect levels to follow
+  * [ ] Crawl depth levels limit
+  * [ ] Document size limit
+  * [ ] Follow external links on crawl
+
+## Environment
+
+``` bash
+apt install git composer php-fpm php-mbstring
+```
+
+## Install
+
+* `git clone`
+* `cd gemini-dl`
+* `composer update`
+* `chmod +x src/gemini-dl.php` _(for direct execution only)_
+
+## Usage
+
+``` bash
+src/gemini-dl.php --source gemini://.. --target /path/to/download
+```
+
+* Alternatively, launch with specified php version `/path/to/php src/gemini-dl.php`
+
+### Options
+
+``` bash
+## Required
+
+    -s, --source     - string, gemini protocol address
+    -t, --target     - string, absolute path to destination folder
+
+## Optional
+
+    -c, --crawl      - no value, crawl document links (entire capsule download), disabled by default
+    -d, --delay      - integer, pause between requests in seconds, 1 by default
+    -i, --index      - string, index filename for directory listing, index.gmi by default
+    -h, --help       - no value, show available commands
+    -k, --keep       - no value, keep original links (--crawl mode only), disabled by default
+    -m, --match      - string, collect links match regex rule, /.*/ by default
+    -r, --raw        - no value, include meta headers (--keep option ignored), disabled by default
+    -u, --unique     - no value, append snap version as folder timestamp, disabled by default
+
+## Experimental (in development)
+
+    -e, --external   - no value, follow external hosts, disabled by default
+    -f, --follow     - integer, follow redirects on --crawl, 0 by default
+    -l, --level      - integer, depth to --crawl, 0 by default
+```
+
+* Manual: `gemini-dl.php --help`