#8 implement interface Source and methods for gitea without Update (#9)

Прикинул метод Open и Delete, Update пока не до делал.

Co-authored-by: Gorbunov Kirill Andreevich <kgorbunov@mtsbank.ru>
Reviewed-on: #9
Co-authored-by: Кирилл Горбунов <kirya_gorbunov_2015@mail.ru>
Co-committed-by: Кирилл Горбунов <kirya_gorbunov_2015@mail.ru>

README.md

@@ -1,2 +1,47 @@
 # pkgdash
 
+# pkgdashcli
+
+## Installation
+
+Use any of the following for a pain-free installation:
+
+* If you have [`go`](https://go.dev/doc/install) installed, you can run:
+   ```shell
+   go install git.unistack.org/unistack-org/pkgdash/cmd/pkgdashcli@latest
+   ```
+  
+## Config
+
+  Before starting, you should fill out the configuration file.
+The file must be located in the .gitea, .gitlab, .github directory
+according to the git type you are using.
+
+- branches - array of main branches
+- source - information about the version control system
+- source.type - type of version control system
+- source.apiurl - path to the version control system api
+- source.repository - repository name
+- source.owner - username of the repository owner
+- update_opt - dependency update options
+- update_opt.pre - update to pre-release versions
+- update_opt.major - compare only major versions in modules
+- update_opt.up_major - raise the version according to major
+- update_opt.cached - caching
+
+### Config.Example
+
+```yaml
+# .gitea/pkgdashcli.yaml
+branches: [master]
+source:
+  type: gitea
+  apiurl: https://git.unistack.org/api/v1
+  repository: pkgdash
+  owner: unistack
+update_opt:
+  pre: false
+  major: false
+  up_major: false
+  cached: true
+```