update deployment documentation

[12rambau]

Fix #1276

I updated the deployment documentation page as Heroku is not providing free services anymore.
I added a note at the beginning explaining why the need for a change and then documented the recommended site by @maartenbreddels: railway.app. Lucky for me the process is nearly the same so I didn't change many things.

Bonus:

• I corrected some indentation issues in the page that were nesting the code-block in admonitions
• I updated the css of the documentation to use the voila color instead of the pydata-shinx-theme teal. It works well on both themes

Happy to make downstream modification if needed

[github-actions]

👈 Launch a Binder on branch 12rambau/voila/deployment

[github-actions]

Benchmark report

The execution time (in milliseconds) are grouped by test file, test type and browser.
For each case, the following values are computed: min <- [1st quartile - median - 3rd quartile] -> max.

Results table

Test file	voila-tree-classic.ipynb	voila-tree-light.ipynb	voila-tree-dark.ipynb	voila-tree-miami.ipynb	basics.ipynb	bqplot.ipynb	dashboard.ipynb	gridspecLayout.ipynb	interactive.ipynb	ipympl.ipynb	multiple_widgets.ipynb	query-strings.ipynb	reveal.ipynb
Render
chromium
actual	72 <- [75 - 81 - 97] -> 137	68 <- [72 - 81 - 100] -> 141	59 <- [62 - 65 - 77] -> 104	54 <- [57 - 61 - 70] -> 79	2456 <- [2498 - 2617 - 2824] -> 3959	2174 <- [2197 - 2202 - 2304] -> 2585	2496 <- [2529 - 2579 - 2705] -> 2863	2275 <- [2332 - 2343 - 2500] -> 2585	1897 <- [1952 - 1989 - 2071] -> 2217	3343 <- [3427 - 3585 - 3845] -> 4801	3676 <- [3683 - 3703 - 3826] -> 4060	1619 <- [1646 - 1693 - 1713] -> 1773	2591 <- [2610 - 2614 - 2730] -> 2999
expected	3379 <- [3442 - 3517 - 3701] -> 3876	2976 <- [3227 - 3321 - 3421] -> 3604	3608 <- [3623 - 3709 - 3793] -> 3825	4453 <- [4453 - 4523 - 4661] -> 4748	2559 <- [2655 - 2656 - 2660] -> 2674	3982 <- [4079 - 4213 - 4356] -> 4743	12183 <- [18509 - 19553 - 20811] -> 21515	15319 <- [15660 - 15796 - 15912] -> 16056	1517 <- [1920 - 1997 - 2103] -> 2113

❗ Test metadata have changed

--- /dev/fd/63	2023-03-03 17:03:12.708229747 +0000
+++ /dev/fd/62	2023-03-03 17:03:12.708229747 +0000
@@ -4,49 +4,49 @@
     "BENCHMARK_REFERENCE": "actual"
   },
   "browsers": {
-    "chromium": "97.0.4666.0"
+    "chromium": "94.0.4595.0"
   },
   "systemInformation": {
     "cpu": {
-      "brand": "Xeon® Platinum 8370C",
+      "brand": "Xeon® E5-2673 v3",
       "cache": {
-        "l1d": 98304,
+        "l1d": 65536,
         "l1i": 65536,
-        "l2": 2097152,
-        "l3": 50331648
+        "l2": 524288,
+        "l3": 31457280
       },
       "cores": 2,
       "family": "6",
-      "flags": "fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology cpuid pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single pti fsgsbase bmi1 hle avx2 smep bmi2 erms invpcid rtm avx512f avx512dq rdseed adx smap clflushopt avx512cd avx512bw avx512vl xsaveopt xsavec xsaves md_clear",
+      "flags": "fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology cpuid pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm invpcid_single pti fsgsbase bmi1 avx2 smep bmi2 erms invpcid xsaveopt md_clear",
       "governor": "",
       "manufacturer": "Intel®",
-      "model": "106",
+      "model": "63",
       "physicalCores": 2,
       "processors": 1,
       "revision": "",
       "socket": "",
-      "speed": 2.8,
+      "speed": 2.4,
       "speedMax": null,
       "speedMin": null,
-      "stepping": "6",
+      "stepping": "2",
       "vendor": "GenuineIntel",
       "virtualization": false,
       "voltage": ""
     },
     "mem": {
-      "total": 7281278976
+      "total": 7291699200
     },
     "osInfo": {
       "arch": "x64",
       "build": "",
-      "codename": "Jammy Jellyfish",
+      "codename": "Focal Fossa",
       "codepage": "UTF-8",
       "distro": "Ubuntu",
-      "kernel": "5.15.0-1033-azure",
+      "kernel": "5.8.0-1040-azure",
       "logofile": "ubuntu",
       "platform": "linux",
-      "release": "22.04.2 LTS",
-      "serial": "b19978ad27ef4e12840827283b4b81b5",
+      "release": "20.04.3 LTS",
+      "serial": "cfc067bfcb844f35865e279a1b0e66c5",
       "servicepack": "",
       "uefi": false
     }

[martinRenou]

Thanks! Would be great to make something similar to https://github.com/voila-dashboards/voila-heroku for railway, would you like to help create https://github.com/voila-dashboards/voila-railway ?

[12rambau]

@martinRenou sure, could you assign some issue to me so that it appears in my dashboard ?