Update register/submit/pw-change for screenreaders

The three important files, next/{register,submit,pw-change}.{md,html}
no longer have images in them (besides the logo at the top of the image
which has nothing to do with registering, submitting or changing
passwords); instead the text in the images are actual text (in some
cases, just the relevant parts and in others all or almost all).

The png/register.* and png/submit.* images were removed.

next/submit.md

@@ -11,11 +11,6 @@ might be offline and unreachable as a website.
 
 To login, open [https://submit.ioccc.org](https://submit.ioccc.org)
 in your browser. Fill in your login credentials and click "Login".
-It might look something like:
-
-<img src="../png/submit.login.png"
- alt="submit server login page screenshot"
- width=710 height=344>
 
 **NOTE**: if the contest is NOT open you will see something like this instead:
 
@@ -34,28 +29,50 @@ Once you've logged in, you will see submit slots. Each slot is for one
 submission so if you update a submission, make sure you choose the right one so
 you do not replace the wrong one!
 
-Here is what it looks like without any uploads and no slot selected:
+It will show text and radio buttons for each row (up to 10 numbered `0` through
+`9`):
 
-<img src="../png/submit.slots.png"
- alt="submit server submission slots list to select from with no slot selected
- screenshot" width=710 height=806>
+| Select | Slot Information   |
+| -------| --------------------
+| 0: [N] | Status: slot empty |
 
-Select a slot and then select a file by clicking the button "Choose File". After
-doing this, it should look something like:
+The `[N]` is a radio button. Tick that to select that slot. Then further down
+the page you'll see the text along the lines of:
 
-<img src="../png/submit.slot-file.png"
- alt="submit server submission slot selected with a file chosen to be uploaded screenshot"
- width=717 height=865>
+> IMPORTANT: Upload only XZ compressed tarballs whose filename is:
+>
+>    `submit.7ec754d4-8670-421a-a1b6-7dd3dc5f215e-SLOT.TIMESTAMP.txz`
+>
+> where `SLOT` is a slot number, and `TIMESTAMP` is the build time as a [Unix
+timestamp](https://unixtime.org/).
+>
+> We highly recommend that you use `mkiocccentry(1)` to create your submit file as
+it must pass the `txzchk(1)` sanity checks, and when the uncompressed tarball is
+untarred, the resulting directory must pass `chkentry(1)`.
 
-If you need to change the file to upload, you can mouseover the file and click
-it. If you wait a moment it'll show the current filename.
+**NOTE**: the `7ec754d4-8670-421a-a1b6-7dd3dc5f215e` is your UUID. **MAKE SURE
+YOU CHANGE IT TO YOUR UUID**!
+
+**NOTE**: the `SLOT` and `TIMESTAMP` **in the filename** are generated based on
+your input in `mkiocccentry(1)`.
+
+Now select the slot you need and then scroll down and click the link that says:
+`Choose File`. A file select option in your browser should open up. Browse for
+your **XZ compressed tarball** that was **generated by `mkiocccentry(1)`** and
+then click whatever button your browser has to upload the file.
+
+You can see the filename of your **XZ compressed tarball` that was **generated
+by `mkiocccentry(1)`**  you're about to upload if you mouseover it and wait
+a moment; if you have made a mistake in your file selection, you may click the
+link that says `Choose File` again. Fix your mistake by choosing the correct
+file in the file selection pop-up in your browser.
 
 Once you're certain you have selected the correct file, click "Submit", below
 the file selection step.
 
 When it's uploaded it should say something like:
 
-> • Uploaded file: submit.9971ada4-b6ae-427d-a7ec-e67a30362cdb-0.1740838915.txz
+> • Uploaded file: `submit.9971ada4-b6ae-427d-a7ec-e67a30362cdb-0.1740838915.txz`
 
 And in the slot it will give you important details like:
 
@@ -69,6 +86,10 @@ tarball listing).
 - the upload date.
 - the SHA256 hash of the file.
 
+Again the `7ec754d4-8670-421a-a1b6-7dd3dc5f215e` is your UUID, the `SLOT` is the
+slot number and `TIMESTAMP` is the build time as a [Unix
+timestamp](https://unixtime.org/).
+
 Now if you're done, log out.
 
 If, on the other hand,, you upload a file that is too big you will see something
@@ -91,16 +112,16 @@ package it with `mkiocccentry`!
 
 If later on you log in and see something like:
 
-> Status: server slot error code: 1! Use mkiocccentry to rebuild and resubmit to
-this slot.
+> **Status: server slot error code: 1! Use mkiocccentry to rebuild and resubmit to
+this slot.**
 
 or:
 
-> Status: submit file failed the txzchk test! Use mkiocccentry to rebuild and resubmit to this slot.
+> **Status: submit file failed the txzchk test! Use mkiocccentry to rebuild and resubmit to this slot.**
 
-... or **ANY** other error then you **MUST FIX** your submission, repackage your
+... or **ANY OTHER ERROR** then you **MUST FIX** your submission, repackage your
 tarball with `mkiocccentry` and upload to the same slot again! If you do not fix
-this your submission **WILL** be rejected for violating [Rule
+this your submission **WILL BE REJECTED** for violating [Rule
 17](rules.html#rule17)!
 
 After the submission deadline is reached, you can log in to check the status of
@@ -108,11 +129,11 @@ your submissions. This is what it will say when the judges have verified
 that your tarball / submission has been validated (NOT judged), by `txzchk(1)`
 and `chkentry(1)`:
 
-> Status: the format of this submission has been validated.
+> **Status: the format of this submission has been validated.**
 
 **IMPORTANT**: this does **NOT** mean that your submission does not violate the
 rules or that everything is OK once the tarball is extracted; it simply means
-the tests performed by the tools passed. If you find a flaw in the tool and
+the tests performed by the tools passed. If you find a flaw in a tool and
 abuse it and the tests pass then you stand a significant chance of having your
 submission rejected for violating [Rule 17](rules.html#rule17), even if the
 tests passed.