proj: Release v0.8.0

- proj: Bump version to 0.8.0
- proj: Release version 0.8.0
- refactor: Run the code through gofmt.
- doc: Update README.md file.
- doc: Prepare release notes.

feat: -get-notification-state implemented.

-get-notification-state flag requires a receipt ID provided by Pushover, which is only done when sending priority (P2 / emergency) messages. Nudge automatically prints that receipt already.

This flag allows tracking the state of the notification and prints the state in a human readable format, however this output can be easily parsed if required.

feat: Add receipt printing and quiet mode support.

- refactor: Run the code through “gofmt”.
- fix: Read values from the newly set variables in “applyFlags”, instead of the supplied flag.
- feat: Implement receipt printing for priority 2 messages.
- feat: Implement “-quiet” flag to suppress receipt printing.
- doc: Update “README.md” for better in-progress tracking.
- doc: Update “RELEASE_NOTES.md” for better progress tracking.

fix: General polish, fix and refactoring.

- refactor: Clean irrelevant and completed “TODO:” tags from codebase.
- fix: Prevent crashing if the default log level is not written correctly.
- fix: Do not perform recipient verification if “-devices” flag is not used.
- feat: Implement string comparison also in Turkish to allow i ↔︎ İ and ı ↔︎ I insensitivity.
- proj: Bump version to “0.8.0a1” to prepare implementing new features.

docs: Update README.md.

Make README.md better, and more current.

fix: Fix internal version number.

This commit fixes the version reported by “-version” flag.

proj: Release version 0.7.0

- proj: Bump version to 0.7.0.
- proj: Release version 0.7.0.
- refactor: Demote Panicf() calls to Fatalf() to disable stack trace printing.
- feat: Finish implementing verify_recipients function.
- feat: Add print_recipients function.
- bug: Handle -retry-interval flag during sending messages.
- bug: Handle -retry-interval flag during configuration sanity checking.
- refactor: Change "_" character to "-" in command line arguments.
- refactor: Change the place where configuration sanity is checked for better user experience.

feat:Continue implementing recipient verification.

This version adds a simple proof of concept loop to verify recipients before sending messages. The loop is incomplete, and needs serious work at this point.

Continue implementing `verify_recipients` function.

Function implementatin is slightly progressed. Need to do a relatively cheap,
fast, and case & locale insensitive comparison next, which needs some research.

proj: General dusting off and polishing.

- refactor: Fix pushoverValidationResponse to PushoverValidationResponse. Types start with a capital letter.
- refactor: getDeviceList returns PushoverValidationResponse instead of raw JSON.
- refactor: Go through gofmt.
- proj: Leave a marker about what to do next in nudge.go.

feat: Continue implementing recipient validation.

- feat: Continue implementing verify_recipients function.
- feat: Implement JSON unmarshalling to a data structure for verify_recipients function.
- feat: Complete Validation API request function.
- refactor: Add "dryrun mode" line to runtime configuration dump.

feat: Continue implementing verify_recipients.

This commit continues to implement recipient verification feature.

- feat: Continue implementing verify_recipients function.
- feat: Get user device and license information from Pushover.net.

feat: Lay groundwork for recipient verification.

- refactor: Remove unused arguments from readAndApplyConfiguration() function.
- proj: Bump version to 0.7.0a1 to denote alpha nature.
- feat: Lay the groundwork for "verify recipients" feature.

refactor: Move project source to repository root.

This commit moves the “src/“ folder to root folder of the project, effectively eliminating it. It’s done to align the project more with the Go project organization conventions.

feat: Add image attachment support.

- proj: Update copyright year.
- feat: Finish implementing image attachement support.
- feat: Implemented file type detection support.
- refactor: Remove warning about image attachments' state.
- refactor: Go through gofmt.
- docs: Update README.md for the new version.
- docs: Update RELEASE_NOTES.md for the new version.
- proj: Bump version to v0.6.0.
- proj: Release version v0.6.0.

feat: Read file to memory as a byte array.

This small commit replaces the file open code with reading code which
actually reads the file contents into a byte array. Next step is to
BASE64 encode it and, attach to the notification itself.

feat: Continue implementing image attachments.

- feat: Continue implementing file attachement logic.
- feat: Start calling the attachImageToNotification function.
- feat: Implemented file size checks in attachImageToNotification function.

feat: Start implementing image attachment support.

- feat: Add relevant flag for attaching images.
- feat: Start implementing image attachment functionality.

refactor: Move go.mod and go.sum to src/ folder.

This commit moves go.mod and go.sum files to src/ folder. That’s the correct place for them to be in the first place.

proj: Finalize v0.5.0.

proj: Finalize v0.5.0 and release to the world.